Quote Originally Posted by Niwashi View Post
Well, in lieu of physics, some additional clever animations for handling wide sleeves when you raise your arms would help, too.
They could theoretically do this, but it would involve having additional bones on robes that drape when the arm is raised. I don't know how they typically handle armor changes in relation to the character skeleton, but adding/ subtracting bones, and as such redoing all animations for specific clothing items is probably not something anyone wants to do.