ActUp used to give managerial lessons for leftist organizations. Of the materials I saw, one of the things they used to teach was that a truly flat organization results in informal hierarchies developing, by the people most capable and/or passionate (because they're motivated by the issue primarily). But then these people are most likely to burn out, because without formal recognition of the power they need to achieve that role or the formal hierarchy in place around them, they end up taking too much on themselves to cover the holes.

But they were talking to leftist organizations. Often these people had communist / socialist / anarchist ideologies, so you can't just tell them: "Implement a hierarchy". And even when they weren't leftist, they were often all volunteer organizations, so you had the same problem anyway.

So their solution, was that when you set up a new organization, you start with it flat. You identify who takes on what roles, and define those roles formally. As you define those roles formally, you define what people have to do to get into that position, clearly and openly.

And that's it. You're still flat, because the positions appear to be emergent. You have a hierarchy, but no one feels like they're stuck under the rule of a shit boss, because everyone in those positions are meritocratically elected, there's now a culture of free movement between positions and definition of positions, and what you have to do to move from one position to another is transparent, instead of opaque as a way for people above to keep their position of authority.