The top men will have harems and many children. They will probably share power and wealth with their sons and daughters (or in-laws), and if it's not enough for

The top men will have harems and many children. They will probably share power and wealth with their sons and daughters (or in-laws), and if it's not enough for the sons to have their own harems, they'll have a wife or series of wives. And in a few generations the huge amount of children from the elite will have diluted their wealth and power significantly. So the result is that most women and a few men will have offspring, the rest of the men are exterminated from the genome. A future generation of people having a lot of cousins, with all the genetical diseases it brings. Every new significant invention means massive genetical extermination of males and a new cycle of power struggles. A stable society with monogamy and equality among people is a rare breather.