^hehe, you're absolutely right.
OK, I've introduced a way for the walker to ... turn. I was caught off by the AT-AT, which had no obvious mechanism for twisting the legs in the xy-plane. I figured you could do it by alternating step lengths, but without rotation in xy, you have to drag the foot to bring the walker back on course, which is just not elegant.
So, I've introduced rotation via a split footpad, with the motors internal. Re-rerigged to fit.
I'm also working on the walk cycle still - not smooth enough yet, but I think I've made good progress on it - update when I feel more comfortable about it.