With power at just 4MJ (Peewees probably have far more firepower than that) you can penetrate 70km of diamond even if the hole is a little less than a millimeter wide you are still going to be cutting through 40k tanks like a hot knife through butter, remember making massive holes in armor isn't the goal penetrating the armor is, and according to the manual the damage isn't just from the laser but the resulting spray of plasma as well.
Wow, so according to you once you penetrate the armor of a tank or ship or aircraft or person or what have you actually being able damage the insides is irrelevant. The reason I laughed at making a .3mm hole in armor is because a .3mm is so tiny that even if it was bored out by a laser and it sprays the plasmafied armor out of the hole there's simply not enough mass there to do any significant damage. Unless of course you get lucky and hit something volatile like the magazines, but that goes for any weapon and since your micro dot laser is making such tiny holes you're far less likely to hit those critical locations.
Anyway why do we have to go purely on game mechanics and visuals? In a standard vs debate isn't going by gameplay bad debating? Isn't fluff always considered higher canon if there is no set canon heirarchy? Going by gameplay in Starcraft, Terran marines can conceivably take on battlecruisers and win. In TA using pure visuals we can get megameter trees by going off the speed of light, using gameplay calcs we get megatons of firepower being thrown out by the big units like Krogoths and Peewees dishing out kilotons of firepower, which kind of coincidentally goes with the fluff like having 200 units deliver gigatons of firepower on the enemy or reduce planets to bedrock with ground fighting. In gameplay units have trouble with simple pathfinding due to ai limitation in the game engine but in fluff every single unit has thousands of years of combat experience downloaded into their minds so should we go with the limitations in the game engine or fluff?
Since a core part of TA and your argument is their resource system is part of the game mechanic we have to discuss it. We just don't do it in game mechanic terms with hitpoints and units of metal and energy and trying to scale the size of trees we see during gameplay. I've been treating the opening cinematic as higher canon since as a cinematic it has no gameplay elements in it and can be treated as a look into the "real TA" if you want to treat it that way. Trying to scale TA from gameplay itself and getting kiloton range Peewees is just as stupid as saying Terran marine rifles can destroy battle cruisers.
I noticed in the laser test if you change the duration and material the hole can be made much wider a 4 MJ laser focused at a microscopic level firing for approximately 1 millisecond on tungsten can expect to penetrate 13.2m of solid tungsten leaving a 9.31mm hole in just 1 millisecond of firing (drill rate is stated to be 13.2km/sec)
You're still ignoring the point the site makes that very high aspect ratios are unlikely. Since you like How to Build a Laser Death Ray;
As a hole is being drilled, material which is ablated from the bottom of the hole by the laser can be re-deposited on the sides. Ejecta from the laser escaping through a deep, narrow hole can also interfere with the incoming laser beam. In addition, the hole itself blocks off the outer fringes of the laser, resulting in less light reaching the bottom of the hole, less energy absorption, and thus the next step of the hole is of narrower width, leading of a constricting taper as the hole gets deeper. All of these effects serve to limit the depth of the holes created by heat rays and blasters. Ray beams may be immune to these effects, since their plasma is transparent to their high energy radiation, and the beam maintains a plasma channel for the remainder of the beam to shine through
Practical experience with laser machining is that aspect ratios of 10:1 are easily acheivable, while the largest practical aspect ratios are about 20:1. Under highly controlled conditions, machined holes can obtain aspect ratios of 40:1 or even 100:1, but conditions in the field are not likely to allow such very deep holes for most death ray applications
In addition, higher power pulses and shorter duration pulses allow higher aspect ratio holes. Blasters are characterized by very short, high power pulses. It is thus reasonable to guess that blasters could routinely reach aspect ratios of 20:1, 30:1, or even more.
Once you reach a certain point all you're going to be doing is making wider holes. If you want a better 4 MJ laser gun try this:
Beam power: 100 TW
Beam diameter at target: 1 μm
Beam duration: 1E-09 s
Beam energy: 100 kJ
Number of pulses: 40
Time between pulses: 10 μs
Total Beam energy: 4 MJ
Total Beam duration: 0.4 ms
Which gets you this in Tungsten:
Material damage from pulse train
Width of hole: 3.5 cm
Depth of hole: 70.1 cm
Aspect ratio: 20
A hole that's large enough to actually cause meaningful damage (it's about the same diameter as modern sabot penetrators), has enough penetration to go through a reasonable amount of tank armor and it doesn't have an absurd aspect ratio. Although I think 4 MJ is actually rather low for a modern MBT round, which are closer to 8 or 9 MJ if not more.