How do I make poses and animations work with all body types?

Hello, I'm working on replacing a couple of the sims animations using sims 4 studio and blender. The only problem I'm having is that I can't figure out how to make the arms adjust according to the sims' body types. When I make my sim bigger, their arms stay in place and collides with their torso, and when I make my sim skinnier their arms look unnaturally spread apart. How do I fix this?

Also, would it be possible to make the animations adjust according to the sim's heights, if I were to downolad a height slider mod? If so, how?