This is how Juju learned her front hip. She was really struggling with them at the gym and was no where close to getting it. I don't typically play coach but I saw this drill and let her work on it at home. In no time she had it! She was only 5 and had it before all her other team mates who were much older then her. It is a great way for them to feel the speed required and learn to no drop their bottoms which was my DD's biggest problem. I am glad to see it being shown so prominantly here. I wish more coaches were more familiar with this drill.
I've seen that drill before, but I don't know. I'm sure it helps some, but I tried it myself, and it didn't feel much like a front hip circle to me. Could have been the tucked aspect. Maybe I should try it piked. I mostly teach it the pike/end part from a position like halfway through the circle (piked around the bar with head at 6 o clock under bar), do three "swings" back and forth, and then "sit up."