so what is the most in depth simulation for a kinda nation v nation battle game. like Caesar where you control alot but more

the only thing i could think of is empire earth 2? which i have no knowledge about. and i remember a game called Theocracy which looked pretty complicated and in depth (kinda old though) but im not sure if i remeber the right game. other those that i have no real idea about what kinda games cause i dont usually play RTS, more of an RPG TBS guy

so plz help