It's been years and I only just now realised that in English this is the CRY relationship. I hope that's not an omen. But maybe they're a Hurt/Comfort trio.
I honestly see Chika this way. The true reason you become a leader in a Love Live! group (that's not just you and your sister) is by having a harem. Honoka is totally that way. Mari is Chika's only real competition. Honoka has to out-"do" Eli and Umi. MC in Superstar may be challenged by Kuku