I just played your game and would say that I'd personally prefer the main (harem) story to be progressing much faster. I'm OK with Hanna but don't that much care about her and even less care about the rest of the side girls.There are 4 mains, all (kind of) part of the family, and that's more than in enough, but that doesn't mean the side girls don't matter, or that they won't get much content.
So, for me the main girls are just enough for now. But that's just me...