Again, why not? These things happen in real life.
She sure as hell wasn't the most important girl during Englehart's run, nor Jones', nor Marz', nor for a good part of Johns'.Yes, but Carol has always been the main one. That's why I cited those examples outside of the comics, because those usually represent a franchise boiled down to their key characteristics. Hal Jordan is one of the main Green Lanterns and Carol Ferris is his main love interest.
Yeah, he had Lana Lang and... Lana Lang.And, as I've said, many heroes have had multiple girlfriends/boyfriends, including even Superman. However, most of them also have their main love interests.