I am calling you on that one. How in the world can your back scap stay pinched and still make a move to the ball? The very thing you make fun of (a one piece, spin swing) is exactly what would happen if your back scap stayed pinched.
You are way off the mark with those comments. In the PCR/Nyman/Englishbey swing, the back scap would unload/unpinch well before contact. Totally different arm action involved here, and the back scap remaining pinched is very much related to the role of the top hand/arm in the swing - which differs by 180 degrees from the PCR blueprint. Study clips of the top guys in ML and you will the arm action is as Tom describes. A revealing difference between lead arm vs. top hand emphasis.
Mike