Trying to make a custom raceswap, but now its animations crash the game!

[Ebontope]

For context, I'm attempting to make a raceswap for a 3.3.5 client of WoW, involving retroported BfA models from another patch. I've tested these models and they all seem to work fine without causing crashes.

The patch that contained these retroported BfA models was encrypted, but I've managed to partially decrypt it by inserting a custom listfile. This way I raceswapped a Tauren Male into a Night Elf Male by exporting and replacing all of the Tauren Male .m2, .skin, .anim and .blp files with the Night Elf Male files. The reason I've done it like this is because I want to later retexture the .blp files to turn Tauren Males into Drow Elves.

Visually this seems to work just fine and most animations seem to work, but whenever the character sits down, after a short while its animation begins to glitch out and devour the world, causing the game to crash.

I've tried looking through the game's base patches for .anim files that I might missed, but I seem to have them all. Retaining the old Tauren Male .anim files does not seem to work either, as it instead just causes even more animations to glitch out and crash the game.

Does anybody know what could be causing these animations to glitch out, and how I could potentially fix it?