A bunch of 40k Imperials on a Starfleet ship in the Trekverse (RAR!)

[Zor]

In this scenario just after the Federation Klingon war in DS9's run the Dominion War Q decides to have a bit of fun and as such snatches some guys from the Warhammer 40,000 Imperium of Man types and puts them on an umanned Galaxy class ship in the Alpha Quadrant a few light years from Bajor. These guys include...

• 300 Imperial Guardsmen, including a few officers all from the same regiment with various bits of IG equipment (including a Leman Russ)
• 500 various enlisted voidsmen from the Imperial Navy with various functions including some flight crews and pilots (they also have a trio of Lightning fighters in the shuttle bay)
• 25 Imperial Navy officers, among them the captain of an Cobra class Destroyer.
• 50 adepts of the Administratum
• 30 Tech Priest of the Adeptus Mechanicus lead by a Magos Explorator (who's concluded that this ship is Dark Age of Technology human stuff)
• 200 General labor servitors
• 20 Priests of the Ecclesiarchy
• 10 Commissars
• Two Sisters of Battle with full general combat gear
• One Space Marine battle brother with full general Space Marine combat gear

The ship has a full federation Databank on hand with information on explored space, Treknology, local politics and similar as well as Federation Cultural information as well as useful instructional documents for how to operate the ship without blowing it up.

What happens?

Zor

[U.P. Cinnabar]

They blow the ship up.

Cause the cogboys started tinkering with the damn thing, relying on prayers and incense instead of accessing the databases, caused a warp core breach, and thought praying to the Omnissiah would fix it.

[Lord Revan]

They blow the ship up.

Cause the cogboys started tinkering with the damn thing, relying on prayers and incense instead of accessing the databases, caused a warp core breach, and thought praying to the Omnissiah would fix it.

Actually unless the lore has changed very drastically since I last checked, the Cult of Omnissiah uses decent engineering knowledge only in highly ritualized form, so prayer and incense will be involved but they do have a degree of knowledge as to what they're actually doing even if it's in the form "this how it's done don't question it". So for example turning on a computer would be "say the prayer of awakening then press the power rune(aka the power button)" while we'd just press the button but they wouldn't expect the payer by itself to do anything.

Also I'd suspect they'd be extra careful with a dark age relic, since no self-respecting techpriest would want to be responsible for loosing a dark age relic due to carelessness.

[Dass.Kapital]

Well.. since there's no 'One' actually in charge of the bunch as a whole.

Then they'll all tend to work at cross purposes at best.

Of note is there's no over all commander of the Guard's men. The OP seems to think the Commissars will do all the organizing.

I've never been sure/clear on how the Ecclesiarchy actually view the Space marines. After all.. they are sort of 'direct descendants' (Kind of... if you squint... ) Of the God Emperor..... *Shrug*

Whether the Magus sees eye to eye working 'With' any body would also be the thing.

Yep... not a lot that I'd think would be anything really 'Progressive' until certain 'Cross purposes' etc work themselves out and one faction comes out completely on top. (So.. basically an empty... possibly semi-gutted ship with one, lone Space Marine...? )

But, um unless it's a really progressive Space Marine? Then every one and every thing in Federation space is eventually in for a bad (Exterminatus) time... Unless something like a Ferengy comes along first and steals/enslaves everything, of course.

[Cykeisme]

They blow the ship up.

Cause the cogboys started tinkering with the damn thing, relying on prayers and incense instead of accessing the databases, caused a warp core breach, and thought praying to the Omnissiah would fix it.

Like Lord Revan said, the higher-ups in the cog-fondler cult understand shit, and the lower down ones are taught rituals so that they perform procedures correctly by rote.

So the lower ranks of Techpriests would never "tinker" with unfamiliar equipment. Either it was built by xenos or hereteks and is tech-heresy (in which case they don't touch it), or it's human-designed and built, in which case it's holy and they will only interact with it in ritualized ways.

The mid-level ones would not be averse to the idea of accessing the databases and doing exactly what it says, treating it as religious texts.

Anyway, in their own universe they build, maintain and operate far more powerful ships on a daily basis.

[U.P. Cinnabar]

They blow the ship up.

Cause the cogboys started tinkering with the damn thing, relying on prayers and incense instead of accessing the databases, caused a warp core breach, and thought praying to the Omnissiah would fix it.

Actually unless the lore has changed very drastically since I last checked, the Cult of Omnissiah uses decent engineering knowledge only in highly ritualized form, so prayer and incense will be involved but they do have a degree of knowledge as to what they're actually doing even if it's in the form "this how it's done don't question it". So for example turning on a computer would be "say the prayer of awakening then press the power rune(aka the power button)" while we'd just press the button but they wouldn't expect the payer by itself to do anything.

Also I'd suspect they'd be extra careful with a dark age relic, since no self-respecting techpriest would want to be responsible for loosing a dark age relic due to carelessness.

You make perfectly valid points, though I have to wonder if that holds true for technology from another reality which is not derived from an STC. On the other hand, they would, as you and the OP pointed out, consider the the Love Boat to be an STC itself, and they do study how xenos tech works, even if it is heresy to use such.

Das.Kap, Zor probably did expect either the Astartes and/or the Commissars to organize everyone, and get them working together, on the assumption that, absent any Inquisitors, everyone would instantly defer to the Astartes and/or the Commissars.

That assumption, though, depends on the chapter from which the battle brother hails, his rank, his level of experience(especially in operating any of the chapter's starships), and who he is(Cato Sicarius, for example, would most certainly take charge), just as it would hinge on the seniority amongst the Commissars, whether any of them are Naval Commissars, as opposed to Imperial Guard ones, whether any of them happen to be Heroes Of the Imperium, and their interactions amongst themselves, as Commissars don't always play nice together(e.g. The Traitor's Hand), and most of them are not Ciaphas Cain, Stephan Yarrick, or Ibraham Gaunt.

The Sisters will likely attach themselves to the three companies of Guardsmen, probably leading them, along with the Astartes and one of the Commissars. The main question here is whether the cogboys can understand the replicators well enough to maintain the lasguns, chainswords, bolters, flamers, heavy weapons, auspexes, comm beads, body armor, powered armor*, and, especially the Leman Russ; if so, they won't have to worry about ammunition or their gear breaking down irreparably.

Mastering the replicators will(okay, may) also allow the tech priests to modify the Galaxy's weapons and defenses to include lance batteries, nova cannon, heavier torpedos, void shields, armor, and the like, though, with no navigator, they're stuck using the ship's warp core.

The Administratum drones, unless this motley crew somehow manages to conquer a planet or two, will mainly be archiving data records from the ship's computers, while the voidsmen, the servitors and the cogboys can operate the ship. The ecclesiarchs will be busy providing moral support for the others and trying to convert the people of this reality over to the Imperial Cult.

And, if Q becomes too much of an asshole, the Astartes and the Sisters are trained to fight gods....

*and, that's not even taking into account the other toys the Adeptus Astartes have at their disposal. Also, is this Astartes from a tactical, assault, Devastator, veteran or Terminator squad?

[Lord Revan]

Well how the Machine Cult of Mars views technology is rather simple if it's made and designed by humans it's holy be a STC tech or my phone. Yes they do study Xeno tech but that's reserved to the higher ranks of the Cult (and even there it's atypical) your typical low to mid level member wouldn't touch a xeno device with a proverbial 10 ft pole, as it would be seen as major heresy.

You got remember as a rule of thumb technology in the Imperium is still a lot more advanced then what we got today.

[Purple]

One thing to consider about all those crazy rituals when it comes to technology in 40K is that they just might not be that crazy. Remember, we are talking about a universe where hell is real and it's a realm of endless magic constantly leching on every single life form. And this chaos that's thus present everywhere has been known to posses and generally screw with technology. For all we know that incense being burned when you press the power button actually does have the power to ensure some sort of chaos energy does not instantly jump into the powering machine and screw up your hard drives if for no other reason than due to the latent power of the combined belief of all techpriests in the fact that it does.

[NecronLord]

They can’t replicate their own tech base. Most likely they find out it is M3 return to earth and seek out the (their faith tells them) hidden emperor to warn him of Horus. Then die quietly of old age.

[Eternal_Freedom]

Plot twist: the Emperor in M3 is actually Ben Sisko.

[NecronLord]

Well.. since there's no 'One' actually in charge of the bunch as a whole.

Then they'll all tend to work at cross purposes at best.

Of note is there's no over all commander of the Guard's men. The OP seems to think the Commissars will do all the organizing.

There's a Navy Officer; he'll presumably be in charge.

I've never been sure/clear on how the Ecclesiarchy actually view the Space marines. After all.. they are sort of 'direct descendants' (Kind of... if you squint... ) Of the God Emperor..... *Shrug*

Sisters see marines as sub-human mutants (SoB codex 2nd edition) although the Emperor created them, to the Sisters they are tools the Emperor intended to serve humanity (they're right here) and a sub-human breed morally; half of them turned on him and condemned him to the throne; the loyal ones must forever be contrite and obedient. Even loyal marines don't worship the Emperor properly; it's a frosty relationship.

There's little love lost between sisters and loyal marines and sisters have purged marine chapters in the past for deviance.

Anyway, in their own universe they build, maintain and operate far more powerful ships on a daily basis.

Yea and Nay. The knowledge to build an imperial starship is not held on all worlds - many components such as warp drives and plasma cores are only found on some forge worlds. These specific tech-priests are explorators, which is a different discipline.

One thing to consider about all those crazy rituals when it comes to technology in 40K is that they just might not be that crazy. Remember, we are talking about a universe where hell is real and it's a realm of endless magic constantly leching on every single life form. And this chaos that's thus present everywhere has been known to posses and generally screw with technology. For all we know that incense being burned when you press the power button actually does have the power to ensure some sort of chaos energy does not instantly jump into the powering machine and screw up your hard drives if for no other reason than due to the latent power of the combined belief of all techpriests in the fact that it does.

No. We regularly see hereteks and innovators who do without the praying and they work things just fine. Sometimes they produce better stuff than the AdMech. On other occasions technology used by others is used by the Imperium with praying and chanting, while others use the same technology with a button-push.

For instance the necrons gifted/traded a supply of necrons weapons called Tesseract Labyrinths to the Grey Knights to help them fight chaos (their mutual enemy), and the Knights have invented a ritual to turn it on that is entirely superflous to how the necrons said it works. Necron lords just push the button. It works as well for the necrons as it does for the Knights; better in fact as it's stated that the ritual makes it harder to suck a daemon into the trap because by the time you're done holy hand grenading it the daemon has had the chance to run off or stab you.

[U.P. Cinnabar]

They can’t replicate their own tech base. Most likely they find out it is M3 return to earth and seek out the (their faith tells them) hidden emperor to warn him of Horus. Then die quietly of old age.

Except, in the 40K canon, Humans don't have any FTL travel until M18, when they discover the Warp. So this isn't even their universe. No Emperor.

On the other hand, this is where the ecclesiarchs come in handy. No one has to know this isn't their past, do they? And, they have to have some purpose to keep them working together.

(besides, they have to be more than a little put out that Mankind works side by side with the filthy xenos in this reality. Have to save the "hidden emperor" from those filthy xenos, after all...)

[Lord Revan]

Well the thing is that things that happen pre-30k are known only to the very few, doesn't take that much to assume they were simply mistaken about when earth gained FTL since much of the knowledge of that era is lost in 41st millenium.

[Joun_Lord]

Except, in the 40K canon, Humans don't have any FTL travel until M18, when they discover the Warp. So this isn't even their universe. No Emperor.

Could still be the past of 40k. As Lord Revan said it could just be shoddy records. For the Imperium 10s of thousands of years later after several pretty much apocalyptic ages where much knowledge was lost, the exact date of human FTL might be off.

Could be correct......from a certain point of view. Maybe FTL as we know it was invented in M18 but they had previous less efficient designs that were not considered true FTL because they didn't travel through the Warp. The Warp Drive of the Federation could operate more like the Tau FTL drives where it "skips" across the surface of the Warp rather then traveling through it.

The 40k guys are going to downright baffled on just how calm the Immaterium is assuming they can cobble together a proper War Drive.

[U.P. Cinnabar]

Could still be the past of 40k. As Lord Revan said it could just be shoddy records. For the Imperium 10s of thousands of years later after several pretty much apocalyptic ages where much knowledge was lost, the exact date of human FTL might be off.

Could be correct......from a certain point of view. Maybe FTL as we know it was invented in M18 but they had previous less efficient designs that were not considered true FTL because they didn't travel through the Warp. The Warp Drive of the Federation could operate more like the Tau FTL drives where it "skips" across the surface of the Warp rather then traveling through it.

You know I realized that possibility just after I clicked "Submit." The Ecclesiarchy and the Inquosition have been redacting Imperial/Human history, especially everything to do with the Age of Strife and the Dark Age Of Technology, so, it's entirely possible that history ain't what the motley crew of Imperials were taught in schola.

And, the ecclesiarchs probably know that, and will do everything in their power to keep everyone else in the dark.

(of course, the last time someone tried to pull a fast one on the Adeptus Sororitas....)

The 40k guys are going to downright baffled on just how calm the Immaterium is assuming they can cobble together a proper Warp Drive.

Relatively speaking. While it's not the roiling pit of Hell that it is in M41/42, the Warp is still kept pretty lively by the Eldar, the Orks, the souls of the murdered Old Ones, and various daemons and other creatures of Chaos, including, IIRC, the three original Ruinous Powers.

(then, you have to wonder why the AQ powers haven't run slap up against the Eldar yet, since they should be fucking like rabbits and overpopulating the Galaxy, and the crew might also get it in their heads to warn the filthy xenos that they're going to spawn Slaneesh in a few millenia, and why that might not necessarily be a good idea.

Also, if the Trekverse is the 40K past, Mars should've been terraformed for two hundred years now)

[NecronLord]

They can’t replicate their own tech base. Most likely they find out it is M3 return to earth and seek out the (their faith tells them) hidden emperor to warn him of Horus. Then die quietly of old age.

Except, in the 40K canon, Humans don't have any FTL travel until M18, when they discover the Warp. So this isn't even their universe. No Emperor.

Yes, I know that. These people do not, they are religious and do not have a concept of quantum alternate universes, while time travel is a fact of their existance.

On the other hand, this is where the ecclesiarchs come in handy. No one has to know this isn't their past, do they? And, they have to have some purpose to keep them working together.

(besides, they have to be more than a little put out that Mankind works side by side with the filthy xenos in this reality. Have to save the "hidden emperor" from those filthy xenos, after all...)

Mankind was known to do that in the past before the Age of Strife.

[NecronLord]

The 40k guys are going to downright baffled on just how calm the Immaterium is assuming they can cobble together a proper War Drive.

No possibility exists of this. None, nada, zip zilch nil nothing.

Warp Drives require the mass resources of a forge world to build one. The most secret and sacred of knowledge. The rarest of physical resources. Billions of tech thralls toiling to purify the materials, the most exalted of archmagi veneratus to build them.

The Lathes, a trio of three extremely producive forge worlds, assembles a few warp drives per year.

That's like thinking Picard can build an anti-matter reactor and warp drive if landed in Westeros.

[NecronLord]

(then, you have to wonder why the AQ powers haven't run slap up against the Eldar yet, since they should be fucking like rabbits and overpopulating the Galaxy, and the crew might also get it in their heads to warn the filthy xenos that they're going to spawn Slaneesh in a few millenia, and why that might not necessarily be a good idea.

In no way am I suggesting it is the factual past of the 40k setting. That's nonsense.

What I am suggesting is that people who know time travel is 'a random bullshit that happens to you' (educated imperials) would presume time travel over alternate universes (which only the necrons know of in 40K).

[Joun_Lord]

You know I realized that possibility just after I clicked "Submit." The Ecclesiarchy and the Inquosition have been redacting Imperial/Human history, especially everything to do with the Age of Strife and the Dark Age Of Technology, so, it's entirely possible that history ain't what the motley crew of Imperials were taught in schola.

And, the ecclesiarchs probably know that, and will do everything in their power to keep everyone else in the dark.

There would be good reason to redact in this case. Running with the insane theory that Trek is a prequel to 40k, look at the state of the galaxy by the perspective of the Imperials.

Humanity is part of a large Federation of Xenos, human kind regularly successfully breeds with Xenos including Eldar (Vulcans) and a violent warrior race that they'd swear were possible proto-Orcs (Klingons) among other Xenos, Holy Terra has been threatened by a race of half mechanical Xenos that are probably out of the Mechanicus's wet dreams......assuming they can still have wet dreams, and humanity uses a type of FTL that might be considered profane by the Adeptus Mechanicus that they travel using intelligent machines.

Other then Holy Terra being a paradise other then all the filthy Xenos putting their filthy paws on its holy soil, M3 sounds like a nightmare to them.

And the Tellarite do no exist. They never had. To say otherwise is heresy.

Relatively speaking. While it's not the roiling pit of Hell that it is in M41/42, the Warp is still kept pretty lively by the Eldar, the Orks, the souls of the murdered Old Ones, and various daemons and other creatures of Chaos, including, IIRC, the three original Ruinous Powers.

(then, you have to wonder why the AQ powers haven't run slap up against the Eldar yet, since they should be fucking like rabbits and overpopulating the Galaxy, and the crew might also get it in their heads to warn the filthy xenos that they're going to spawn Slaneesh in a few millenia, and why that might not necessarily be a good idea.

The Eldar are peaceful and with good relations with the humans, the Orcs have not been discovered yet, and the power of Chaos is so weak the the Eldar and any other psykers have never show any sign of their influence. The galaxy is relatively peaceful.

No possibility exists of this. None, nada, zip zilch nil nothing.

Warp Drives require the mass resources of a forge world to build one. The most secret and sacred of knowledge. The rarest of physical resources. Billions of tech thralls toiling to purify the materials, the most exalted of archmagi veneratus to build them.

The Lathes, a trio of three extremely producive forge worlds, assembles a few warp drives per year.

That's like thinking Picard can build an anti-matter reactor and warp drive if landed in Westeros.

The resources exist to build a type of Warp Drive even if its not the proper one or one that is anywhere even close to being sanctified. They even have one to study in the bowels of their ship, assuming it doesn't explode when the Space Marine farts near it.

Again running with the idea of Trek being the past of 40k, the Warp Drive of Trek seems to be similar technology but clearly different. Far slower, doesn't use physic navigation, doesn't seem to travel through a realm of unending torment. Its seems very similar to the FTL employed by the Tau.

Clearly there has to be some common tech between the Warp Drive of M3 and M41. Though the question is how much? It could be the difference between a steam engine and nuclear turbine. Similar in many respects but woefully different technologies. The Trek Warp Drive could be primitive enough to be useless at reverse engineering into a proper Warp Drive.

One thing that might be interesting is the fact that they do considering Warp Drives so sacred. The fact everyone is building these primitive steam engine Warp Drives left and right could probably give them quite the purge boner.

[U.P. Cinnabar]

Mankind was known to do that in the past before the Age of Strife.

Work alongside Xenos? Yeah, but these guys think xenos=bad thing, even if the Imperials worked with them a few times in the past(e.g. First Gothic War, Gravalax Incident), the history of which would be under Inquisitorial seal for the most part.

*That Rom's mommy dresses him funny*

In no way am I suggesting it is the factual past of the 40k setting. That's nonsense.

What I am suggesting is that people who know time travel is 'a random bullshit that happens to you' (educated imperials) would presume time travel over alternate universes (which only the necrons know of in 40K).

There was a YouTuber some years ago who made a vid trying to say Roms and Eldar were related. I forget now.

Oh, it's unlikely this is the 40K verse's M3; too many things don't line up(no terraformed Mars, for one), even given the Inquosition and the Ecclesiarchy have made paper dollies out of the historical record. It was idle speculation.

No possibility exists of this. None, nada, zip zilch nil nothing.

Warp Drives require the mass resources of a forge world to build one. The most secret and sacred of knowledge. The rarest of physical resources. Billions of tech thralls toiling to purify the materials, the most exalted of archmagi veneratus to build them.

The Lathes, a trio of three extremely producive forge worlds, assembles a few warp drives per year.

And, these particular cogboys lack the knowledge to build one. Also, certain parts for ST warp engines can't be replicated, let alone components for Warp drives or Gellar field generators. That's a given.

That's like thinking Picard can build an anti-matter reactor and warp drive if landed in Westeros.

You don't know how many fanfics I've read that imply precisely that(or how many idiot YT vids/posts). With Q's help, no less.

Agreed, these Imperials lack the knowledge and cannot manufacture the parts, even if they did.

And the Tellarite do no exist. They never had. To say otherwise is heresy.

The Tellarites would argue with that.

Again running with the idea of Trek being the past of 40k, the Warp Drive of Trek seems to be similar technology but clearly different. Far slower, doesn't use physic navigation, doesn't seem to travel through a realm of unending torment. Its seems very similar to the FTL employed by the Tau.

Except the Tau warp drives do access the Warp; just at its lowest levels, and only for short intervals.

Leaving off the fact that, out-of-universe, Trek fans, writers and producers have tried to make ST warp engines fit whatever "theory" that's convenient for them at the time(with the fandom's recent attempt to make Trek warp engines fit Alcubierre's math, for example), the closest 40K analogue(though by no means the best fit) to Trek warp engines would be the Necrons' FTL drives.

Clearly there has to be some common tech between the Warp Drive of M3 and M41. Though the question is how much? It could be the difference between a steam engine and nuclear turbine. Similar in many respects but woefully different technologies. The Trek Warp Drive could be primitive enough to be useless at reverse engineering into a proper Warp Drive.

Dude, that just gave me horrid visions of subspace creatures eating people's brains and doing experiments on th...oh, wait, shit, that was a TNG episode, wasn't it....

Anyway, the two drive systems work on different theories.

ST warp drives warp spacetime to go FTL*, while 40K Warp drives access an alternate physical reality underlying the material universe. So, it wouldn't be a matter of the ST warp engine being too primitive to back engineer into a proper Warp drive, the two drive systems are just completely dissimilar from one another.

*the how or why is where all the various fan, writer, producer and studio theories come in, but that's a headache for another time.

[NecronLord]

Running with the insane theory that Trek is a prequel to 40k

Jesus fuck I'm sorry I posted it now.

[Joun_Lord]

The Tellarites would argue with that.

How can they argue if they don't exist? They have never existed and even if they had they were eaten by space bugs.

I'm sure you have already figured it out but just incase you haven't, I'm referring to the GW stance towards the Squats. The Tellarites are probably the closet thing to space Dwarves in Trek.

Except the Tau warp drives do access the Warp; just at its lowest levels, and only for short intervals.

Leaving off the fact that, out-of-universe, Trek fans, writers and producers have tried to make ST warp engines fit whatever "theory" that's convenient for them at the time(with the fandom's recent attempt to make Trek warp engines fit Alcubierre's math, for example), the closest 40K analogue(though by no means the best fit) to Trek warp engines would be the Necrons' FTL drives.

Dude, that just gave me horrid visions of subspace creatures eating people's brains and doing experiments on th...oh, wait, shit, that was a TNG episode, wasn't it....

Anyway, the two drive systems work on different theories.

ST warp drives warp spacetime to go FTL*, while 40K Warp drives access an alternate physical reality underlying the material universe. So, it wouldn't be a matter of the ST warp engine being too primitive to back engineer into a proper Warp drive, the two drive systems are just completely dissimilar from one another.

Presumably when a Trek vessel activates its warp field creating a subspace bubble, the bubble is like a pocket of the warp that is used to skim along the surface rather then diving in fully much like Tau do.....or did. Doing some research there seems to be some debate as to whether or not the Tau still even have FTL.

Now thats probably nowhere near how it operates in reality (well the fictional reality) but assuming Trek is the past of 40k there should be some overlap between the Warp Drive on M3 and the one of M41. Atleast I'd assume so.

Jesus fuck I'm sorry I posted it now.

Why?

Its insane in a good way, like the theories about Doom or Event Horizon being prequels to 40k. Trek being the past of 40k, the Vulcans being the Eldar, the Rommies being Dark Eldar, and somewhere the Emperor is farting about changing crap in the shadows (probably running Section 31) is just insanely awesome.

If I was still into writing fan fics I'd love to take a crack at the concept.

[U.P. Cinnabar]

I got the Squat reference, J_L. I was just making a Tellarite joke, referring to their famous...err...pigheadedness.

Its insane in a good way, like the theories about Doom or Event Horizon being prequels to 40k. Trek being the past of 40k, the Vulcans being the Eldar, the Rommies being Dark Eldar, and somewhere the Emperor is farting about changing crap in the shadows (probably running Section 31) is just insanely awesome.

If I was still into writing fan fics I'd love to take a crack at the concept.

I think I'm going to be as sorry as NecronLord. As sorry as a Custodes caught with his Tau girlfriend.

[Lord Revan]

Looking at location of the Core of the Eldar pre-fall civilization (roughly at centre of what's "now" the Eye of Terror) and when it was at its zenith (15M-20M according to the Eldar Codex I have with the fall being at 30M), it's "possible" for the Eldar to exist in ST without having been seen yet. Greenskins pose a problem though.

[U.P. Cinnabar]

If I compared the two galactic maps correctly, Segementum Obscurus(where the Eye Of Terror is located)coincides with the Gamma Quadrant, and the GQ is, as of yet, largely unexplored by the Feds, possibly even by the Dominion as well, so it's entirely possible the Eldar homeworlds haven't been found yet.