Model swapping problem. Any Ideas?

Alright, so here’s the deal. I’ve been using the left 4 dead 2 Nick model for a video I have been making, and unfortunately it has turned out to be a bad decision on the long run. I have about 30 nick models representing different random goons and, to be honest, it looks quite ridiculous as you can imagine. What’s even worse is that due to him using the left 4 dead 2 skeleton, other models that I could attach to him all use the half life 2 skeleton, so they look all horribly deformed.

I’m wondering if there is a way to get past this problem? I out of ideas and if any of you could think of a way to bypass this it’d be a godsend.

Sorry if this isn’t the right thread btw.