Those early large societies were evidently transitional, though. We wouldn't expect the egalitarianism that was prominent in the Stone Age to have disappeared overnight with the rise of sedentary social norms. The new hierarchies had to take shape and establish themselves through some more trial and error.

Could we so easily go back to an egalitarian, non-hierarchical society? Could we put any such inspiration into practice, now that the civilized norms have set it? It's not so clear.