They are originally .m2. I export them as .fbx using WoW Model Viewer, then import into 3ds Max. In 3ds Max I remove unnecessary bones, separate the mesh, add the animations, create the materials. Then I export to .mdx with NeoDex.
lol nice, I was thinking that maybe models created in wowhead page are diferent because I can't get them to load in wowmodelviewer once I get the files from firefox cache, like I've done with hive models uwu