I truly love this tribe-themed manga.
The author was right; in old tribal custom, your capability as a man is the main criteria of getting woman (or in some cases, women)
This is not purely a matter of wealth (like those gold diggers).
It's about respect, trust, and distribution of roles.
The wife(wives) take care of the farmland and the cattles, while the husband hunts for food so his family won't starve.
The husband often faced with danger when hunting, often gone a full day (sometimes for days) and even then he's still burdened with responsibility to provide an acceptable living quality for his family.
For all the effort he spent, the wife(wives) will return the favor by providing warm meal, take care of their household, educate their childrens, etc.
It's the oldest form of household. Thing that many millennials have discarded and forgotten for their pursue of career, fame, and wealth.