As I played through the demo, I noticed that non western countries are still fairly weak compared to their western counterparts, so a suggestion would be ( i will already mod it to see how it goes) to lower land maintenance proportionally to the tech cost ( and eventually a bonus to manpower and forcelimits). So the hordes will really be hordes, and aztecs could really field massive armies, generally speaking given that units besides western are really crap ( and I am really lazy to mod units one by one
), 2 or three line of codes could really balance things out fairly well .