Certainly looks like it might be heading in a harem direction now, which I know is going to disappoint some people on this thread, but... honestly? Yuri harem is still relatively uncommon as subgenre intersections go, so I'm not that bothered. Yeah you could argue that it's a little trashy, but with the straights having so many proudly trashy harem stories, I think we gaysbians can live with a couple here and there.
To me, the thing that decides how tolerable a yuri harem story is how it wraps up. The "stretch out the question of whether X ends up with Y or Z" into eternity/people stop caring option is the clear worst, but most yuri harem stories end with either a singular couple forming, or some kind of poly arrangement, which are both valid.
Plus if I had to guess, it seems like this one is angling for a single core pairing with third wheels for drama, which is a time-honoured structure for romance stories.