[Daryl]

To get back on topic:

Now you're throwing in a number of components and efforts required to maintain rhythm. These efforts would be far less critical if the clubhead and the hands had the same RPM.

There are three Rhythms that relate to the three Hinges. Each procedure is unique. The only similarity is that the Flat Left Wrist and Clubface rotate simultaneously around the Hinge. Each Hinge Action - Rhythm - rotates the Clubface about a different Plane. Vertical, Horizontal and Angled. Certainly you can accomplish that with the Left Wrist alone. But Swingers and Hitters have "Inherent" Hinge Action because of the way the Right Forearm participates, which is caused in part by Wrist Action. Parts within Parts. Motions within Motions.