Looks like the game is culling polygons because the model is over the defined "acceptable" polycount, could also be that you need to recalculate normals on the model, but cape textures are applied with a two-sided flag, so it's unlikely. Try to decimate the cloak models in Blender, might fix it.
Some of Draenai hairs use the horn textures, so that one hair wich is ONE mesh use 2 textures!I try a lot in the skin file to switch it but it have no effeckt just if i go to the horn texture it switch.And in model viewer it looks normal.A tip for you : This is always define in the Skin01 fileTry to search the submesh ID of the hair, then look up the TextureUnit with the same idSubmesh[153] is hair ? Then Check TextureUnit [153]As you can see on the wikihttps://wowdev.wiki/M2/WotLK/.skin#Texture_unitsThere is a Texture field in the textureunit struct, it's a wrong value that cause ur problemTry values 0 1 2 3 4, until you got the correct texture
Those "buggy" cloaks were problem with some WoD char models ported to WotLK by Alastor. I am not sure if he fixed it, you may want to ask him.