Funny, I think it's precisely the opposite. I don't think most creative people can thrive under a strict hierarchy (some famous creative people had even trouble to keep a normal job).
It's true that groups of creative people sometimes cooperate, but almost always like equals. One of the famous counterexamples I can give you is the Monty Python collaboration, which was strictly democratic. There are also plenty examples of creative collaborations between two people.
In open source software, where there is a hierarchy, it is rather informal. Linus is not a single "lead architect" of Linux; would he enforce a bad decision that most developers would disagree with, he would be forked away. He has no choice than to respect meritocratic wishes of other developers, if he wants to stay "in charge".
There were open source projects that tried a more heavy handed way of architectural management, and they failed - such as GCC or XFree86.