I'm just never going to advocate carrying a bunch of different molds on a message board...kind-of for the same reason I don't curse in movie theaters during Disney movies.
Very well said, and great rationale. That's why I tried to give so many examples of different ways to play practice round -- must of which emphasize minimal discs and learning how every disc you have flies for all possible types of shots.
I think one of the best things most people could do for their game is play for a few months with just a putter. Then add a midrange and play that way for a month or two, then add a neutral driver and finish out the year with those three discs. It would be a hard challenge for most people, but I think if you did it with friends, it would be fun and keep the competition lively.
I could see a 123/321 challenge being a great idea. You and your friends all make a six-month commitment. For the first three months you get one disc (putter), for the next two months, you get two discs (putter,midrange), for the last month, you get three discs (putter, midrange, neutral driver). At the end of six months, you get your whole bag back... if you want it. I bet most amateur players would learn more in six months than in their first few years of play.