hi, ok from the last few games i have played, i think certain nations need less good area´s or they rule too much.
Etiopians and Incans, both rule each game i play at the moment. One i played as American, i had to wipe out the Sioux before they got Archers and Dogsoldiers, because they would have killed me and then found Incan was wiping out about everyone else quickly, so must be earning to much and having too good territory and in Africa Etiopians had devastated all africans and was jumping the middle east and europeans, when i meet the first europeans the Etiopians had like 5 or 6 vassals.
now as Romans, i have all of europa more or less, Etiopia got like almost all of africa and like 5 or 6 vassals and just meet americans and all the rest there and Inca have like all of south america and all nations there is incan vassals
etiopia and incans seems to do this every game and no one around them seems able to stop them, also americans, unless played by a player, will never be able to make it, due to lack of all items of importance. Perhaps give them a horse nearby washington, as iron and copper is so far away for them.