I find with creating cooperative housing situations that a certain degree of common shared values is very important, and then selecting for diversity of perspectives / backgrounds / lived experiences makes synergy easier. Maybe that's also true of communities more generally? When groups are very homogenous, it's hard to resist defaulting to group dynamics that further reinforce that homogeneity because that's what binds the group together; when groups are diverse & find value in their diversity, difference is generally a feature instead of a bug.