[Yoda]

A stable swing center is indeed imperative in my view

Homer Kelley was careful to differentiate the Imperatives from the Essentials.
You cannot deviate from the Three Imperatives -- Flat Left Wrist,
Clubhead Lag Pressure Point and Straight Plane Line -- and play high level
golf. Deviating from the Three Essentials -- Stationary Head, Balance and
Rhythm (close call!) -- makes high level golf far more difficult, but not
impossible. As an example, recall Curtis Strange winning two U.S. Opens with
a very visible lateral Head movement.