As the name suggests, I would a game based around the native mesoamericans, with the Tlaxcala, Mexica and Maya. The Zapotec and other tribes would be great, but these are the 3 most influential at the ideal time to set a total war game. I present to you, TOTAL WAR FLOWER, named after flower wars, a war arranged in advance between allies to obtain more captives. It would take a lot of effort, but this has the potential to be crazily chaotic.