@Zardnaar I’ve found lots of inspiration in Green Ronin’s Mythic Vista line of d20 products when it comes to kinda real-world settings. In particular I like Egyptian Adventures: Hamunaptra; there is a real nice blend of fantasy and inspired-by real world politics. There are some cool monsters, spells, prestige classes, magic items and such, but the best parts are the cultural ideas. I combined bits of GURPS Egypt with Hamunaptra, and plan on doing some conversion to 5e for an upcoming game.
I can't really go and buy PDFs etc ATM. Green Ronin normally makes good stuff.
Also any names for a fantasy Nile? Using the River Nuria atm, any better suggestions with another 2-3 factions would be great.