Rick ... very good.
Would you say that the hip rotation leading shoulder rotation also results in some ER, setting up more effective IR? Said another way, do you feel that the hip rotation leading shoulder rotation leads to what KenB refers to as 'lag' .... and the observance of the palm tilting somewhat more palm-up momentarily?
Yes, I think they are interrelated.
I think of the hip rotation creating shoulder rotation is similar to a plyometric movement......where the intent is to create a rapid "stretch-shortening" of the core transverse muscles to generate an explosive movement.