I'm gonna level with you @asleepymonster , I just spent about a half hour reading through anthropology sources online and i figure you just meant the blanket “polygamy as a blanket category for the marriage of multiple individuals” and not the “all polygamy is polygyny” version. Which in the field the modern use is just... the correct definition. Popular use is a different beast.
For real though i sat there googling for like 45 mins wondering if i wasn’t noticing something and then i remembered most people think the polygyny thing. Or assume it means bigamy--which is a whole different thing and for a second i forgot most people’s only reference for polygamy is cults/Mormons
For the other people reading this post, some definitions:
Monogamy, the union between two individuals.
Polygamy, the union between three or more individuals.
Polyandry refers to a marriage between a woman and multiple men.
Polygyny is the a marriage between a man and multiple women.
Group marriage is a form of marriage where several males are married simultaneously to several females.
Polyamory is the practice of, or desire for, intimate relationships with more than one partner, with the informed consent of all partners involved.
Polycule is used in this sense, as relationships between members of the group can take different forms. Like a molecule of water.
Ok, now that that nerding is out of the way, on to the Tensura nerding.
If you mean serial polygamy as in, as members leave/die, more marry in or if you mean they just keep adding-- honestly it probably depends on whats going on.
I believe the Ogres probably practice polyandry, if only because they canonically keep their numbers low and that means the balances are probably going to skew toward that. Additionally, they probably practice fraternal polyandry--several brothers marrying one woman-- to make sure family power/wealth is consolidated and negates any inheritance infighting. In this way, all the husbands are considered the father of all the children, which means everything ends out a lot clearer in terms of like... who’s in charge next. It’s probably a lot looser for non-nobles, bc then its a lot lower stakes in terms of social capital when they come together. This makes Shuna and Shion competing over Rimuru more significant if only because sharing-- which probably isn’t unheard of-- would complicate matters of like. Social stuff. That said, Rimuru would have to be ok with that and then not nosedive, because he’s a former japanese man that lived of Hentai and dating sims. That’s a whole different post, we’re talking ogres.
Given their long lifespans and their niche as mercenaries, it wouldn’t surprise me if serial polyandry was a thing-- but it would probably be more if their husbands all died and they married into another family. It’d probably be perfectly acceptable, but also i imagine any children from the second union would only benefit from their father’s status-- as any from the mother would apply to the first children. That said, i’m assuming its an eldest thing, because Benimaru being a prince is treated as a big deal. That said, Shuna being a princess is treated about the same in terms of importance. So it might also be an egalitarian version of polygamy. Honestly we don’t see much implying there’s a gender difference in their society so it’s possible they’re on the same level, socially. Hmm meta.
Also who fucking knows with Orcs. Because i know mmm 4 things about them as a people, other than they’re hard workers and based on pigs. They eat a lot, they have a lot of kids, they only group when being driven by a stronger one, and the place they came from before the whole Orc Disaster was famine ridden. None of those facts gives me a lot to work with, because while YES i can look at pig behavior to fill in gaps-- there’s a lot of pigs! Many pig! Which pig are they? Domestic? Those are monogamous when allowed in group settings. Wild hogs--in north america at least-- live separated by gender and only meet up when it’s breeding season. BUT some also just live in groups! What pig are they? Does it matter to anyone but me, who is trying to imagine if their hair is course or wooley? No.
Basically they could practice sexual monogamy, OR marital monogamy. They could have mating seasons and practice temporary marriages that legally end once the resulting offspring are old enough. No hard feelings or w/e, they just go about their lives and either enter a new one or just vibe.
Humans are probably serial monogamists if only because thats the vibe i get from them.
Aaaaand if none of this is what you meant, i apologize but ADHD and otherwise unused College go brrr
