Uhm.. that texture should be a baked npc texture, not a cloak. The last filename specifies the texture for the whole model. I don't think you want a cloak textured troll.
This is not because of your model viewer. That texture just is not a texture that would fit on an NPC. It needs to be a square. And needs to have an npc on it. Just look at other entries in that dbc.
I don't care what you want, I can only say what is wrong and tell you how to fix it. And I did.