I'm not sure if bounding Scythians to Yamnayas is correct. The proof you gave from reddit can applied to middle eastern societies as well; for example Ishtar cults and Elagabalus alongside with Emesan (and Syrian) religion. Even Greeks had rituals when roles of their youth were swapped.
It does not convince me. Tacitus in Germania described Germanics as loyal and honorable and Romans and southerners as whole as degenerate and weak. Same goes for Caesar's De Bello Gallico. Anyway I'm not nationalist nor ethnicist to make a tautology from blood of folk and its culture.

Shame there's so little of blackpillist anthropology yet.
From my investigations flows an image of changes in archaic societies (I won't now go into any details other than I am sympathetic to Bachofen's religious-mythic method, since early societies were all theocracies):
1)A primal order is hypergamism, wherein a small group of chads hold monopoly over hordes of femoids. Those, who are born nonchads are held alive as helpful, since every pair of hands is useful.
2)But such order is unwanted by them. They become outcasts and, since they're majority of men, herds of warriors. They can't alone kill a chad, since they're weaker; Hobbes say even a weakest man can kill the strongest one, but they can't yet organize, because there's no advanced language. These times are preserved in tradition and myth of mannerbund.
3)From their forced concentration in those herds and cooperation being necessary finally rised language. Why not in chads' harem? Because there were no necessarity of cooperation there: every chad was egoistic and rather loner and every particular femoid served them, trying to gain his interest over other parts of harem. Thus when it arised, mannerbunds, being numerous and well organized, slaughtered chads and seized the means of reproduction. Earliest myth to be founds, in Enuma Elish, describe these events as Marduk slaughtering Tiamat and creating a world from her body. So arised a social state of humanity.
4)Religion, the most important part of early social order, was never matriarchal (like Bachofen thinks). Even Assyrian and Babylonian traditions of ritual prostitution (which Bachofen links to primal state of heterism) couldn't be matriarchal, because - what's proven by blackpill - femoids only wants to intercourse with chads. Every early social order was guaranteeing equal redistribution of femoids. There were societies where polygamy was allowed: Celts and Scythians; but they waged regularly wars and after killing enemy tribe, they seized their means of reproduction, assigning those to warriors. Not a single tribeman suffered inkwelldom because of this. Roman and Greek descriptions of these people shows it.
The famous foid figurines, instead of deities, were rather triumphal archs. Even tho there in fact were deities in archaic age, they were never truly femoidic, since the most important part of their nature, that is hypergamy, wasn't preserved in these. It was worship of truecel property in form of foids.
Decline of this state, modern hypergamism and second nonchad revolution are not to describe here.