As far as GL is concerned, I have to agree that until the return of the Corps, the existing Lanterns would be stretched thin, so I don't see any of them joining the League. However, after the reformation of the Corps, there will be five GLs in this sector plus Jade. I think one could be spared to side with the heroes of Earth in planetary defense, especially considering that the Earth of the DCU seems to be the focus of attention for wannabe intergalactic conquerors, space alien monster thingies, and the like.
