Can you explain yourself further because I have no idea what you are talking about? Of course normal sexual behavior and patriarchy are different — that’s my point!
Prior to patriarchy (which arose around the same time as agriculture), who the father of a child was was largely irrelevant. There was next to nothing to inherit, and clan affiliation went through the mother, since everyone knew who a child's mother was. Pair bonding is an ancient practice, but as with the tribes you mentioned, has little to do with sexual practices, which may well have been slightly different from band to band. Plus, if taking care of the group is the primary evolutionary strategy, it hardly matters who the father is from that perspective either. The nuclear family as we think of it with a father and a mother caring for their children alone is a very recent phenomenon.
"Many anthropologists now believe that alloparenting (group childraising) was how the human species survived. Patriarchy has only been around for approximately 3% of human history. The nuclear family, with a father out “providing” and a mother at home “nurturing” is a relatively recent development — even more recent than that. “When politicians lament the ‘decline of the family,’ they have in mind departures from the nuclear family: a man, his wife, and their biological children. However, the template for this kind of family dates back only a century or so, at most to Victorian times, and in American contexts not a lot further than the 1950s, when my generation of baby boomers grew up in mostly single-family homes.” Hrdy, Sarah Blaffer. Mothers and Others (p. 144)."
Additionally, there is every indication that humans are designed to be multi-maters. Everything from the way are genitals are shaped and the functionionality of that to the fact that our closest primate cousins are multi-maters, indicates that this was an evolutionary strategy that humans also employed.
"Comparisons to other primates are especially persuasive. Like humans, our closest cousins, chimps and bonobos, have testes on the outside (though theirs are bigger), and male animals are typically 10 to 15 percent larger than females. Gorillas, though, like more distant cousins on steroids, have small penises (balls on the inside), and males that are twice as big as females. Because gorillas mate polygynously (multiple ladies for each dude), males must be imposing to win access to females (specifically, their vaginas). But for chimps and bonobos, “multimale-multifemale” maters, the battle is on the inside — large volumes of sperm fight to the egg, even leaving traps for competitors. Our genital similarities to chimps and bonobos thus reveal our promiscuous past.(5)"
"The great anthropologist and comparativist Sarah Hrdy tells us that, across species, including among humans, the best mother for many eons was the one who was, under particular and far-from-rare ecological circumstances, promiscuous. By being so, she could hedge against male infertility, up her odds of a healthy pregnancy and robust offspring, and create a wider network of support by lining up two or three males who figured the offspring might be theirs. (5)"
