There's an irony here in that if there were no guardian, builders would (have to) be a lot more careful. But if there's a guardian around, he does genuinely guard the builders from harm as the project goes along.
Even after one year of being in this situation, I'm still not sure if having a guardian is a good or a bad thing.
Also, I think some of the best leaders are neither guardians nor builders by my definition. They are exceptionally good at inspiring others to take one course of action or the other as needed. Perhaps we could call them Charismatic Communicators?