Really only need one of those plot points; too many cooks spoil the broth. And again, the Koopalings need a rest, now, what with NSMBWii and all.
Why do they need a rest when they, quite literally, just re-appeared? And with re-designs, no less? For all sakes and purposes, they've been re-launched as "new additions" to the fold and introduced to a new generation of gamers.
Give me another "mainstream" game, or even a spin-off/RPG appearance, and then I would be more willing to relent. But I'm not about to do so when I can more than likely count on seeing GYAT. DAMN. BABIES. in another (spin-off) game some time soon, much less continue to tolerate the presence of other second-string characters like Petey, Waluigi and Daisy for this last decade and some change.
But hey, turn-about is fair play! Let's talk about Rosalina, shall we? She just did appear in Mario Galaxy, then the following year's Mario Kart Wii, and you can more than likely can count on seeing her
again in MG2. Furthermore, I wouldn't be surprised if she becomes a regular in Mario sports games before they would even think about say, Captain Syrup.
Still, ol' girl is in no danger of being "over-exposed", right...?