The so called "state" is just a burocratic institution. Most Kings/Mighty Chieftains were the personification of the "state". But almost all of those Kings/Governments had to rely on the aristocrathy, local princes, clan leaders etc., who had their own interests and targets. Theoreticaly, one can use those merchants to portrait ancient societies even more detailed, but the question is: what is their particular role in the game, withing the game engine etc.?