Animation won't work on other models

I purchased an animation pack and followed this tutorial:

which teaches one how to retarget animations. I made sure all the models are humanoid like it suggests, and I auto mapped all of the bones. but the purchased animations only work with the models downloaded with them (they bend and twist in weird ways with the other animations), and the other models do the same with the purchased animations. When I remove the humanoid on the purchased animations and models, putting them back to general, the purchased models work perfectly with their own animations, but when they are humanoid they do the bending and twisting thing. Any thoughts?