Well, Paul McB doesn't have the biggest hands and still is one of the best spin putters ever. I'm just guessing that he has to give the disc more speed to get the spin than guys like Eagle, Calvin or Simon.
I wasn't trying to dissuade you (or anyone) from spin putting, but more responding to the idea that some people seem to able to spin putt without as much velocity on the disc, "floating" it into the chains.
Spin and speed are two separate animals. It seems to me that speed relates to arm speed, where spin relates to snap - wrist and fore arm.