I think the whole idea of turning the Trollans into Guardians of the Universe wannabes is a bad notion from the start (and this coming from a rabid Green Lantern fan). Having the Overlords being simply the ruling body of Trolla itself would be sufficient. There's no reason to majorly change the species into something else, or to grim and gritty the whole concept. They were fine as somewhat innocent, somewhat childlike beings with their own kind of wisdom. A good story has a balance between lightness and the dark, and Orko and his people were one of the light elements in MOTU. Orko was the child in us watching all this amazing adventure, and that's an important perspective that the tale shouldn't lose. I have no problem treating the mythos a little more seriously, but that doesn't mean getting rid of the fun.
I'd like to think of them as simply the wisest and most practiced of the magic makers of Trolla, which means Montorq would likely be at least an advisor, if not one of them. I wouldn't see them interfering in other worlds; running the upside down world they inhabit would be a full time job from what we saw in the old days. I think the Oracle we saw in 200x would be something of the model here, still very much a classic Trollan in look and demeanor, just a bit wiser in his own way.