@shortstories - For post-collapse in-group pairings, I would have fathers choose their daughter's husbands. This seems least likely to result in sociopathic matches. No doubt, there would be a few... 🤔 But over the course of generations, that hazard would be minimized through selection pressure.
For post-collapse out-group pairings, war brides would be chosen by the warriors who triumph. After a conflict, women of the adversarial community are divided among the warriors. ➡️
@shortstories - ➡️ Warriors would still be obligated to provide for any war-brides they keep. Any surplus out-group females from a conflict, can be brought back to the in-group community, where they can be sold as brides.
Such a system would incentivize young in-group men to become warriors in hopes of getting their pick of a war bride. And second-tier war brides aren't necessarily doomed or abandoned, but are given a second chance on the market.