The problem with single person projects is there is often not enough feedback and checks on what seem like good ideas at the time. Too many people and suddenly you have management.

This is an awesome quote.

Well, it would be interesting to know if anyone else has any insights as to team-size.   2-3 people seems most typical; teams of 4-5 are usually on two projects at once. And as long as they know how to manage, or are, more likely, under the purview of a project manager who knows how to give them a little distance (but, not too much), it seems to work okay.   But I have definitely found (as Mechanism openly states) that “a project manager who knows everything about project management but nothing about software ... can’t manage a software project.”

Single-person projects, or teams or departments that are led by an autocrat who styles himself “head geek,” invariably are a certain recipe for disaster.   (Especially the latter.)   I think it’s really important that the key people on the team have knowledge of facilitation ... and diplomacy ... as well as above-average technical “chops.”

Single-person projects, or teams or departments that are led by an autocrat who styles himself “head geek,” invariably are a certain recipe for disaster.

CPAN disproves this quite conclusively.

I do not think you can compare CPAN to a department at a company. The difference starts at who shows up there and diverges even more every step of the way.