Working with a pre-made texture

I was looking at using some of the plentiful existing textures available for poser for non-poser models in Blender (e.g. Make Human models).

I thought I’d try to map a free V4 face skin to a MH head, but Blender seems to want to split the mesh up the back of the head even though I don’t put a manual seam there.

Has anyone had success unwrapping to match an existing texture (when Blender doesn’t automatically want to unwrap that way)? Especially success with unwrapping a human form from MH to work with a Daz/Poser character?

Is this a fool’s errand?

Many thanks!

p.s. I’m somewhat aware of Poser Tools 2 ( http://www.blender3dclub.com/index.php?name=PT2 ) development, but since I’m not trying to import an entire poser character, just trying to reuse a texture on another human form, I didn’t think I neede to wait for the whole thing.