v1.6.01 was a small patch that was meant to fix the missing reapers textures but it doesn't as it turns out there was an extra mesh hidden under that cloak which had its texture missing (the death animation removes the cloak so all the meshes are necessary).
Just use v1.6, if GAE complains about missing textures make sure that the Ghoul, Phantom, Reaver and Corpseress all have Reaper_Skeleton.tga and Reaper_Flesh.tga present if they don't just copy the _Skeleton/_Flest (the one that is there) and rename it to the one that's missing and it should work. v2.0 has it all fixed up.
Only got the Harpies, Ice Golems and Wind Spirits left then the Hyperion are done and we're at v1.8. From there I'm gonna reduce some more g3d sizes and maybe 'pngitize' some of the large model textures so that both factions are running along with some final tweaks for v1.9. Then I'm going to add some trees to the menu model and finally release v2.0!
Also I'm forcing myself not to use WoW models, the only one there are the Satyrs and like the Werewolves, they're getting a revamp eventually, I'm gonna have a cool demonic humanoid model rather than the WoWish goat man look they have now. As from other games, I don't think any unit in the Hyperion faction are from another game, actually some are built from 3D model packs for the old Hexen and Heretic games but these are fan made models not from the original game and the models were only used as a base, they have new animations, a modified model and a brand new texture. Basically you'll not see the models used in the Hyperion in any other game.