You're right, so both of them are bad. I know that this is fiction and the guy she will end up with will be commited to her but... the data irl doesn't lie. The more you date and sleep around, the less you actually enjoy new relationships, and the fall off goes down hard after like 4-5 relationships. + if a person sleeps around it means they don't value themselves or other people and just see them as a tool for satisfaction and once you wire yourself like that... it's pretty much over for you.
You really have to ignore reality and suspend your disbelief to enjoy these works.

I dont root for either, one is kissing her sister and the other one sleeps around a lot ew