I think Cozy actually came up with a a pretty great way of dealing with the harem aspect. The fact that the MC is a is a Family head means he's kind of expected to have multiple wives, just like all the other do. So for most of the girls its just normal and expected that they will have to share considering most of them come from one of the families.
Of the few who are not, Lucy is so infatuated with the Mc since he's the only person who has ever really treated her well that she would do literally anything if she though it would make him happy. Victoria is a massive freak and the MC gave her the opportunity to really be herself, so as long as she gets hers she's good to go. And Akatsuki.... well she's Akatsuki.
Honestly Akatsuki is probably my favorite just because there didn't need to be any deep plot justifications for why she wanted to be with the MC. She just does. She saw him, said "yeah I want that" and went for it. Even without the MC she would still likely have followed the same path as Akari, becoming a very skilled cook and probably would have done very well in the restaurant world. So it's the fact that she never specifically needed the MC, she just really wanted him.