Yes, of course. Thats the way the animations are made. I first make a mesh model in a sort of base position (see the "Leonardo"-style image below) that is easy to edit and then i add a skeleton, which transforms the mesh dynamically. Well, of course i have some base meshes and skeletons for the humans and horses so i don't have to make everything again and again . The skeleton has so called "actions", which describe the characters movement and can be switched easily.
This is the dragoon unit: