I don't really like these plots, and having read the first chapter, it seems to me the author didn't think basically at all about how society would be different if only about 15% of the population were male. Even if we assume it had developed to modern technological and organizational standards regardless, nobody would be talking about "enacting polygamy," that would be the assumed default, and boys would not be treated the same as girls, because they're so much more rare and absolutely essential to continuing civilization they would be treated very preferentially and given all sorts of benefits. Gender norms would be completely different, relationship preferences and behaviors would be completely different, and men wouldn't really care about "conquering women" because women would probably be throwing themselves at men all the time hoping to secure a high status spot so it wouldn't be difficult. Basically none of what is in this story is anything like how the world would be, 1:39 is literally a gag manga and it has done a better job at representing how the world would actually be anyway.