I like that, and the wider level ranges are probably better for separating the greater gods from mortals.
I like "Elder Gods" in the hierarchy, btw. One way to envision this is via the scope of their power and influence:
Mortal - terrestrial, mortal
Demigod - local
Lesser God - regional/cultural
Intermediate God - national/continental
Greater God - planetary
Elder God - solar system
Overgod - galaxy
Allgod - universe
The One - multiverse
Or something like that. Doesn't quite work, but the basic idea is what I'm trying to get across.