Regarding the camos, this is my understanding:
To get a skin on a model, there are two major steps.
The first is skinmeshing the model. This essentially is unwrapping all the polygons of the model, and then pushing them flat such that they are all on the same plane. This is difficult enough to do properly and efficiently for a weapon model, even moreso with an organic model (at least in my experience). This flattening process usually gives a unique skinmesh to every model.
The second part is the texture, and obviously the more glorified part. This is what you see, and the process is pretty self explanatory. Its essentially a coloring book type dealie, with the skinmesh serving as the lines to do so.
Now, of course you could try to match the skinmesh of the female model to the skinmesh of the male model. Again, in my experience, this is rather difficult to do, and if not done properly, to the pixel, you'll get huge black seams running up and down your model. However, even if you were able to do this to a sufficient degree of accuracy, you would then have distorted the skinmesh in such a fashion that the skin would not appear properly when applied to the model again.
Hope this was somewhat explanatory.