The shoulders control the backswing. If you have a short shot, the shoulders turn back some, then you rotate through for "x" distance. As the shots get farther, the shoulders still control the backswing, but the hips will be pulled (by the shoulders) around a little bit (keeping the weight forward). The hips do not move on their own.
The power is not in how far or long the backswing is, it is in how efficient the backswing is, AND HOW FAST YOU TURN THROUGH IMPACT TO A COMPLETE FINISH. It is just like throwing a ball... your arm goes back a bit and you turn through for "x", but if you want "2x", you don't take your arms back twice as far, you just turn through faster to throw farther. Hint: Consistency is in the forward commitment all the way to the finish, not the backswing. Most golfers worry way too much about the backswing and think everything ends at the ball... just the opposite... practice a shorter controlled backswing and learn to TURN AND ACCELERATE TO THE FINISH. You would not stop half way if you were throwing a ball.
Move Less ... Get Good! DUPLESSISGOLF