I think the reason why small communities are so often used as an example is that the war complex is the result of a scale problem. Meaning, the larger that human civilization becomes the harder it is to manage and inevitably small communities get into conflict with each other, team up to be stronger, etc. The existence of areas that are peaceful don't seem like a model of what could be applied other places but actually the consequence of war. The unique circumstances presented by other nations distracting themselves with war or maybe an isolated civilization that is not known to nearby community gives the privilege of these small communities to be peaceful.
I think the crux, though, of my argument is that humans have violence and conflict as an inherent part of their nature and the risk of aggression is amplified by sheer number of people alive. So yes small communities might be able to be peaceful but we've never seen the world at peace. Does that mean it's not possible? Technically no. But it seems extremely unlikely