Earlier quoted context omitted.
That's historically the case: https://www.theguardian.com/science/2014/sep/24/women-men-dn... The other implication of polygamy is that a lot of men simply didn't have a chance to pass on their genes at all.
I sometimes wonder if a big reason why monogamous marriage exists as a concept in human society is as a strategy for mitigating violent upheaval. By using cultural pressure to force single-partner relationships (at least on the surface), you no longer had a large group of sexually frustrated men with nothing to lose looking around and wondering how to get a piece of what the elite have that they don't.
Yes, many anthropologists have theorized the same idea. William Tucker (journalist) wrote a whole book about marriage being a social mechanism to reduce violence:
https://www.amazon.com/Marriage-Civilization-Monogamy-Made-H...