While I agree the evidence is somewhat sparse, I think this is more of an issue of ease-of-reading versus rigor, and I think you've struck a reasonable balance.

I think the central thesis of this is, "The 'classic' view of ev-bio/psych that is modeled on the male earner, female caretaker family structure is probably wrong." If that's the case, your argument and evidence seem fairly solid. If you're going so far as to argue some other specific structure, then you're a bit short on evidence. There is an odd tendency to think that 1955 is the paradigm of human society, when it is decidedly an outlier.

I'm admittedly biased. Ever since I read about the history of marriage, I've suspected that the "History is just like 1950's" view is extremely flawed. Even in agricultural societies, mating was not really determined by individuals, but by their families. Cheating was probably relatively infrequent given the control exercised over women and the difficulty of cheating in a small village without lights available in the evening (as opposed to a large city).

I think this is an excellent post promoting an interesting topic, and I expect it is seeing relatively few upvotes because it runs contrary to many people's cherished beliefs.