it's not a matter of easy or harder. you can't rig a human skeleton to a dog model. and that's basically what your implying, that the model doesn't matter.
I've been doing this for along time, and the way your thinking is improper. has nothing to do with easier or harder.. it'sthe fact of properly creating and rigging your model.
if the bone for the arm in the models foot.. your model isn't going to work right. not 1005, not even 15
even if you properly rigged, then just changed the names in order for the model to stretch to the animations.. ITS WRONG