The Scavenger arc was one of my faves, its return is most welcome! Hopefully after its conclusion we get the quick and hasty return of Sarah's nemesis after she got kicked off the island on a boat. Simply put this kind of game NEEDS an antagonist as whilst we've had several (all redeemed or at least getting there) she is the one who had the best motivations in all honesty - desire for revenge made sense given her history, she's obsessed with getting one over Sarah so of course she is not gonna take defeat sitting down and naturally seducing you will be high on the agenda to get what she wants. This can all come with time though, Scavenger arc should remain a light hearted fun arc and its not finished its second iteration yet.
I'm wondering how Hachi will add Jeanne, Zero etc to the main scheme of things asset wise. They've been more peripheral main girls than tertiary side characters as of late IMO but to do that of course more work will need to be done - the hotel does not have another floor of rooms to fill thus given them a place to stay (no, i do not count the cells lol and you are gonna need at minimum three). Job wise i can see them fitting in easy enough relieving Sonja of some of her many burdens (Bank, Cafe and is a bit too much for the girl i would say) or he could just create new roles for them such as say Lifeguard at the beach... something for them to do and somewhere to be through the day.