Their theory is anti-Pivot Lag. The Pivot train is like a three stage rocket in the sense that sequencing occurs but that’s where the comparison ends.
If the first gear slows, then a chain reaction of slowing follows. I agree that Hip motion first must overcome the inertia of the upper body and Club, and that may seem like work because of the effort, and when it subsides people think the pivot has done its job, but I don’t think the turning motion and Right Hip should slow.