Am I mistaken , thinking that the single track clutch has four ( 4 ) governors / weights ?
Not sure I'd go along with the less friction part .
Seems to me that the independent single track weights would have twice as much opportunity to add friction being as the weights could touch the tracks from either side , not to mention double ( or there about ) contact surface of the shaft to the track .
And , theoretically , the weights should be moving at the same rate / time if they and the tracks are identical .
I don't know how the single and double track governors compare for total contact surface to the sliding member of the driven pulley .
Maybe the heavier / thicker single track governor track being wider provides a smoother transition of weight / governor and the 'fingers' , having more mass , absorb more vibration ( = sound ) .
Pete .