For the Greeks, I think I'd shrink it down to only the most famous 3 independent citystates - Sparta, Troy and Athens , and have them constantly shift between being allies and enemies among each other.
I'd set your Roman city right smack in the middle of Augustus transforming the Republic into an Empire - and add in lots of Star Wars references for kicks. Use the clerics of the Roman gods like jedi, for example
I don't want to use historical names. I was thinking of Greece being a non human area that was over run with the Greeks in Crete or western Turkey (or the equivalent map I end up using).
The non humans also wondering where to put them. The Huns are going to be Orcs, Gnolls will be in the desert, Sumeria will be my equivalent of Netheril (and non human), wood elves Germany, high elves England, Halfling in France perhaps, Dwarves in Switzerland and/or Anatolia (Hill Dwarves Anatolia, Mountain Dwarves Switzerland?).
Africa can have the equivalent of Mali, Ethiopia, Great Zimbabwe with perhaps the Jungle areas like Congo doing the dark continent trope. Egypt will be a land of ruins, I want an equivalent of Alexandria under a governor perhaps with perhaps a narrow strip of land down the Nuria (100 miles perhaps) with the rest of the Kingdom in the hands of Gnolls, Jackal men etc.
It doesn't have to be historically accurate. Greek hoplites can have steel weapons or even things like longswords. If they are marching around in close formation they can have things like spellcasters to counterspell fireballs etc.