That period was just the same shit on a smaller scale. The story is told by our genomes and by those of pathogens and parasites - again and again breeding concentrated and bottlenecked, suggesting power accumulation, and again and again entire germlines went extinct, as the old guard were violently usurped - and we’ve plenty of archaeology that shows wholesale slaughter of entire populations.
And… chimps follow the same patterns - accumulation of breeding rights to a select germline, followed by violent revolution, infanticide, all of it. We are cut from the same stuff.