Ethnicities then.Race is a social construct for which we cant define accurately. The biological difference between local populations of people is too varied.
There have been plenty of groups throughout history that have functioned without a hierarchy. Even in societies such as the plains indians or mongolians hierarchy was extremely fluid. If hierarchies were natural why do societies and civilizations fall with such regularity? Why are humans seemingly predisposed to not obey orders. Why do governments have to force people to conform? Hell most ancient societies spent a considerable amount of time just getting kids to listen to their parents.
It gets even more muddied when you add a racial aspect into it eh?
They arent Nazis. Id compare them to the eugenicists and race realists who influenced the Nazis though
I don't know of any society without some kind of dominance hiararchy. I'll look into the ones you mentioned but even still it seems to be the exception rather than the norm. Having said all this every person is different. For instance I have a real issue with doing as I'm told. But I like the fact that in my (and most other) society murder is rare because its illegal for instance.
Societies fail for a variety of reason, outside influences from a more technologically advanced civilization, natural disasters, war, famine etc.