jolietboy - there does seem to be somewhat of a fad about teaching leading with the front hip out of hand break. Look below to see if you can tell me if either Kershaw or Bumgarner is leading with their front hip out of hand break...doesn't look like it to me (Bumgarner maybe slightly).
The reason many want you to lead with front hip is to keep the COM or the core stacked until the right moment. Both Kershaw and Bumgarner are stacked going into rotation right before foot strike....see second pics below. Stacked or the core being stacked is the head is still aligned over the spine, and not tilted off center before & right at foot strike.
I've never cared for the idea of attaching hip motion to handbreak, but that may be because I screw around with handbreak too much to make it a useful cue.