If you compare the V3 Male to M3, you'll see they don't really look too much alike. There are some resemblances, some stronger than others. As dialyn said, they come from the same base mesh. This was a test I did as soon as I got M3. V3M is on the left with HdMale at 1 and Muscleman at 1, M3 on the right without any morphs (I used Muscleman because I thought it most closely resembled M3). Both are wearing the V3M texture.