Mr Kelley defines "Pace" as The surface speed of the orbiting Clubhead - as differentiated from Rhythm.
He urges us (6-P-0) to never make a shot BUT to make a ([non-automatic] release) "Motion".
So, a non-automatic release procedure is invoked in order to produce "Pace" - a steady and constant hand speed, augmented by Trigger Delay to produce the desired effect.
Therefore, there is no connection between "Pace" and "Rhythm" unless a conscious decision is made to keep both lever assemblies at the same RPM - in which event Pace is sacrificed in the interest of maintaining Rhythm.
I think there is a GINORMOUS connection between Pace and Rhythm. Handspeed, fast or slow, relative to clubhead speed is exponentially slower. The surface speed is a result of an extention of the Primary Lever Assembly . . . thereby increasing from a small radius (cocked) to a large radius (uncocking). This increase in radius from the extention of the lever assembly results major velocity . . . but ideally not to the detriment of Rhythm with the Left Arm Flying Wedge and its Flat Left Wrist in tact . . . so surface speed is increasing dramatically but the RPM is the same . . . Law of the Flail.
So the hands can move slow (Pace) but the clubhead can move real fast (surface speed).