If your needs are not simple and you actually have to re-order "every" vert's order to match another model whose vertex size is the same ( and is essentially the same model. Tho I suppose the following is valid for any "UV matchable area" ) Chances are you have committed to UV layouts already and have turned on the…
I agree with cryrid, the UV layout isn't helping at all. It's wasting space and wasting pixels. You could make a few adjustments, straighten some pieces out and utilize more pixels. There is way too much lighting, highlights and shadows in the diffuse material. The diffuse is just color information with hints of lighting…
Piggy backing of what Fabi_G said; It may be a good idea to pick a background painting from your favorite 90's anime, and try your best to recreate that in 3d? That way you will have a clear and definte finish line, while not having to worry about layout/composition.