I've always saw it more as "New Gods" is the race, Genesisian and Apokaliptan as a nationality.
Martians, Daxamites, Tamaraneans, there are a lot of alien powerhouses. They've never really been gauged, and any contest may be decided by other factors. If a Thanagarian soldier beats up a Kryptonian artist or scientist under a red sun, that doesn't mean all Thanagarians are stronger than all Kryptonians.
