GBD
OK. I can understand your viewpoint.
You were simply interpreting that graph which showed that arm speed was not much greater than shoulder speed and that arm speed peaked soon after shoulder speed.
Just as cameras produce artifacts, so do the golf researchers. They confuse us with different graphs. That graph represents the view of "reality" as produced by the TPI researchers. Here is a graph produced by the Welch-Zenolink researchers, and this graph represents their view of "reality" regarding the kinetic sequence.
The blue curve represents the shoulder speed, and the green curve shows the arm speed. One can see that the arms travel much faster than the shoulders after the shoulders decelerate and that the arm speed peaks much later.
Jeff.