If by significantly more powerful than the gods, you mean the Soulswords, then how about they be counted as no more powerful than Divine Artifacts during the crossover? If, however you mean Wulf, Marv, Bug and all the rest, then I'm sure they'd be willing to accept the restriction of only being able to use 3 powers during the crossover none of which can be a mimicry or cause them to be stronger than a minor god. That does of course limit the number of possible fights and makes friendly interactions more likely to occur.