Lots of good intentions here, but -- man-oh-man -- is the devil ever going to be in the details on this one. We've seen this on a much smaller scale when two schools use one PTO, and that very often leads to territoriality and fairness fights, when one group inevitably feels that it either did more work (and therefore deserves more money) or is more needy (and therefore deserves more money). That will only be exacerbated when bringing dozens of groups together.
Would this work in your district? Have you tried anything like it?