[O.B.Left]

but the "surface speed" or ratio of hand speed to clubhead speed
HB

IMO when Homer says "surface speed" he is not referring to the ratio of hand speed to clubhead speed. Surface speed in the context of Rhythm relates to for example a spoke on a wheel. Any point on the spoke will have the same RPM but the further you get away from the centre along the spoke the greater the surface speed. ie the clubhead given a flat left wrist will be travelling at the same RPM's about the centre as the hands but the clubhead will have a faster surface speed .

HInging will for sure have its effects on the surface speed of the clubhead given any #3 angle but the clubhead for vertical is still moving faster than the hands given a flat left wrist , Rhythm.