How do i get my characters who share the same skeleton, but have different proportions to animate correctly regardless of their proportional differences?

I am working on a game and i’m new to setting up modular characters and i really need help. My characters all use the same skeleton and they all work with the same animations. For example, the characters with the same proportions as the base skeleton all clap correctly and their hands touch, but the larger characters with slightly different proportions all clap, their hands don’t come near to touching when animating, due to their different arm proportions. I’m sure i need to set up base poses and such, but I’ve been looking around and i’m not finding much. I’m am learning unreal, i just need help with this please. I’m sure it has something to do with base, poses and the re-targetting manager, but any help/ a walk through would be super useful.