I like this idea! Especially gods you can't tell apart. That's a great touch. Hell, that's enough to build a setting on right there.

What geographical scale do you think we can make this work on? It sounds like a whole continent to me, maybe a bit less than a whole continent, but you definitely want a North African/Near Eastern/Western Asian kind of feel to the biome. Largely arid, desert and plains, but with huge deltas and inland seas and stuff like that.

Would love to help but I may suck at name generation as I don't speak any Semitic languages at all...