The crux of the matter is this (and I don't think I can say it strongly enough)...
The Head is related to the Left Shoulder (by the simple fact that it rides on the plane of the shoulder girdle) which is the Low Point of the Swing.
If your Head moves to the Right or to the Left of the Center of the Stance, the Low Point moves thus, you have to either...
1) Move it back to Center at impact or,
2) Shift your aiming point forward (if your head shifts right of center and stays there through impact) or backward (if your head shifts left of center and stays there through impact) to allow your club to get into an in-line position and not hit the ground first or the top of the ball or,
3) Have a ball position that already FACTORS in the amount of 'sway'.
With all due respect, if you have to ask me, "What are you talking about; can you elaborate on these compensations?", then use a Stationary Head Center.
Again, if your answer to the question "Can you make these 'compensations' at the same time, all the time?" is less than an affirmative 'YES!', use the Stationary Head Center.
The crux of the matter is that the nature of the power package alignments and the way best to plan the shoulder motion's dynamically moving line per law of the triangle into impact.
You see the impact alignments that Homer Kelley pointed out relate to the primary lever assembly and the right forarm positioning - if you see the power package you have two which are under the constant control of the hands to precise alignments however if you visualise you can see yet another triangle from the left shoulder to the right elbow. By just using the primary lever alignments and right forearm alignments this triangle sits on a plane - this plane can be rotated on a line from the right elbow and the only means of control you have to this triangle is the amount of elbow bend. Elbow bend at fix is an amount in degrees and as such the best you can have a close approximation with the intention of the stationary head allowing enough leeway with the point between the shoulders that the right shoulder thrusts to a point (hip slide) before spining on its axis without significantly affecting the nature of the power package alignments mid stroke. This is fine tuning...
If you move the head out of its constant stationary position...suddenly the whole clubhead orbit and how your alignments operates, changes during the downstroke and becomes out of presise control. You turn a mechanical advantage into a thing that requires compensation. This is on a different radio show altogether...
The stationary head is a wonderful thing. The centered arc is the fundamental bedrock (as Jack Nicklaus might say) of G.O.L.F.