well, technically, torso-twist should not be useable on mechs like the locust or jenner or so, because the torso is wedged between the legs. thus the whole mech would have to turn around. but of course, that would make those mechs horrendously bad in CBT, so they went without it.
Same reason in Star-siege, all those Designs were HERCS with Torso between legs, thus, no torso twist . .
and in the MEchwarrior games, mechs with legs up to their ears and the torso in between NEVER had torso-twist either . .
Flea for example.
only humanoid machines get torso twist, because they have a turret like torso/rump joint.
