The gods all came to this universe from the same place, and are all essentially the same kind of being, which is why they are all basically equal in power. It's why they can live in harmony the way they do because, honestly, none of them are better. The only ones that have made it through the rift are equals. The rift they use is the only one leading to this new universe without any real definition(When they arrive at least) however if you like the idea of other rifts opening up, we can play with that later too :P So yeah, they all kinda blundered through one rift and after coming over decided to stabilize it just in case they wanted to go back, but now most are happy in the new universe so it's more for the transients from their home universe.

That is, if you like the idea.