Parenting what's now called the waist to the body actor was, if I recall correctly, Diogenes' idea. I think it makes for much easier posing since one can now manipulate the (anatomical) hip independently. Because the hip actor is traditionally parented to the body, that's how we originally did it, until we learned of the problems this caused for WW.

The new naming corresponds a little better with the actual human anatomy, which I guess was relevant for WW matching clothing geometry to the figure. But I'm sure Phil will be able to explain it better. At any rate, since neither body -> waist -> hip nor body -> hip -> hip2 worked perfectly with everything, I think going for the more "natural" naming convention was a good decision in hindsight.

-- I'm not mad at you, just Westphalian.