Your point is generally correct however much of the perceived center snap "rhythm" is dependent on two distinct and separate variables:
The Center calling out blocking schemes based on the play to be run; and
The QB making audibles that impact and effect the interior blocking schemes being called by the Center before the snap is actually accomplished.
If you remember the National Championship Game a few years ago when Bama was playing I believe Notre Dame and were beating them pretty badly into the 4th Quarter, there was a major argument on the field prior to a play being run by Bama's offense because the Center and QB were doing their jobs and the QB forgot that the Center retains Veto Power until he snaps the football.
The starting Bama Center; "Barrett" and QB-AJ McCarron were yelling at each other after the QB called for a time out when the play clock was running down and he (McCarron) was coming off the field yelling at Barrett who was yelling right back at him.
If you watched the replay the QB-McCarron was clapping his hands for the Center to snap the football, but Barrett (Center) ignored that demand because he (Center) had to get the offensive line blocking correct for a blitz by the Domers. So either McCarron changed the play requiring a blocking adjustment, or the Domers shifted into a blitz requiring a split second change to be made by the Center before the ball would be snapped to prevent a potential disaster from happening.
They rythm of the shotgun snap can be easily picked up by watching the QB clapping for the football, or the center bending his headdown looking at the QB then squaring up momentarily for a second prior to snapping the football. So a D-Lineman can guess right or jump offsides and look stupid if the Center is changing up blocking schemes for a multitude of reasons.
Reinforcing the point that everyone involved in the game knows first hand, and that is the CENTER is the most critical piece of any play being run correctly BEFORE ever snapping the football to the QB.
