From watching other shows, I've noticed giving the lead couple too much screen space in essence kills the show itself. You run out of stories and start putting up crap. Moreover, the audience is either sick of seeing the same thing or so addicted to the one couple that all other elements remain irrelevant. So in consequence the characters and story lose depth, emotion and meaing.
I think having Sameera will allow further understanding of Maan's character and we might see why she broke his heart considering her positive role (bet you NT had something to do with it). This might also bring out a jealous Geet which will be HILARIOUS to watch - worth its' weight in gold!!!