Let's be real, even the original 765 girls can be summed up by a gimmick. "The twins", "the poor one", "the rich tsundere", "the animal one", "the tomboy", "the shy one", etc.
Yeah, but I think they at least have multiple dimensions to their characters on top of all that instead of being a cardboard cutout.
And yeah, like Metroid said, they play up those gimmicks anyway because that's what idols do, but it's nice to know what kind of characters they are outside of the publicity gimmick they put on for popularity.