Quote - The "gender split" between G2F and G2M allows more exact weightmapping and JCMs, and makes cloth creation easier. 

As an example I did 6 body morphs for G1 and G2. The G1 version required (in order to look good when the thigh bends) 36 JCMs for all of them in the thigh area and reduce the "Exploding butt" syndrome.

The G2 required 4... and that was just because i just wanted the lower glute to look a little better in the bend of two body shapes.