The red marked parts are bad, because they do overlap. The one marked yellow is not that bad, but not good either because it does not overlay perfectly. The other parts overlay perfectly and are good for AO
As you guessed sins has no ingame Ambient Occlusion. Therefore we have only the option to bake AO into the texture using a professional 3D program (I guess blender could do this to). To make use of such a process, the parts that are symmetrical have to be overlayed on the UV pixel perfect and need to be oriented that the AO selfshadow is on the same spot when two pieces use up the same space on the UV.
Example, look at the UV above, then at your texture below
Then look at the AO map I can bake
and now at the combined texture
Using that texture for the model would result in this:
Notice all the improper Black spots? Thats where pieces of the UV overlap that shouldn't. Best example is the black part and line on the vertical wing. If all parts on the UV layout are properly separated and overlayed, the AO looks perfect and the model even more stunning.
As for textureing your models, I could (and I really would want to) but I still have so many other models and things to care about concerning this mod that It would be a great relieve for me if you could do this for us. Still, I appreciate all your models even without texture (but please make the UV)
PS.: If you want to redo the UV on the Vorchan, I will make a proper AO and Light for the texture. I think if you carefully arrange the parts on the UV the texture can be used almost as it is. Otherwise I will take care of the Vorchan UV myself sometime in the future.
Thanks again for helping us with modelling (and UV and textureing) and hope this post helps to understand what I said before.
Have a nice night