Learn to create the stretch between the rear leg and the rear hip by coiling the hip against an internally rotating leg. Just like the ratchet shows. The hip NEVER rotates. It is driven by the rear leg when the stretch is broken. It's called SUDDENNESS OF LAUNCH. Hip rotation is about as slow a launch technique as one could have. Hip rotation is nothing but 'muscling up'. Using two legs is nothing but 'muscling up'. Hip rotation around two legs lacks the mechanical advantage offered by the SnF load/unload. There is nothing sudden about hip rotation. Only with a stretch created by the rear hip resisting the rear leg, by coiling and constantly and continuously pulling rearward, against an internally rotating leg, will you ever find the suddenness that you need to hit high level pitching.
First, let's stop talking about the hips and be more specific. There's the vertibrae, the femur, the pelvis, and the hip joint. I think most people referring to turning the hips actually mean turning the pelvis.The rear leg is the Driver.