GodZilla, I see the problem and you're right, it's a bug. I have no idea what causes it, so I'm gonna try and fix it now.
IMPORTANT NOTICE
Thanks to GODZilla's help, a bug was found with the latest pack which I have promptly fixed. The bug was not with the animations per se, but with the graphical artifacts that occurred in Romans during battles, because I have updated modified their Idle animations. This problem is a result of Vercingetorix's otherwise excellent CAS Script (or it could be caused by the XIDX, not sure), and it has been observed before, when simply modifying certain animations would create graphical glitches in the game. To fix this, I simply took out the updated Idle anims and restored the vanilla ones.