omglol:Even though this seems like a good idea , it would split the community over even more games :/
Well, that's exactly the same thing people said when there was only one X-pack to the game.
Yet, the Asian Dynasties ended up brining even more people to the game, and most fans enjoyed the addition to the game. The community would still be one (AoE), but there would simply be another section for those who bought the new X-pack.
Added that I'm quite sure a bunch of people would buy an X-pack with the European civs. and other ideas (including the Incas) that are in the first post of this topic. I'm sure it would be an instant seller, considering the amount of fans that would be satisfied with this addition.
LoboSoldier:for example african civilizations, because mostly of them were under european control anyway, so it could be like keep playing with the same Europa civilizations.
Prior to the era of colonization, there were various prominent African Empires and historically famous civilizations (such as the Zulu) that battled the European colonization of the area.
LoboSoldier:but it is a good idea to improve the both expansion packs(The Warchiefs and Asian Dynasites) , for example adding AOE more primary natives civilizations like Incans and Mayans besides the Iroquis, Sioux, and Aztecs. Some Asians civ like Korea, and some europeans like Italy, Austria and Sweden, at least those are historicaly real powerful civ so it makes sense to put them.
Thanks. The more people that favor the idea, and the more contributions, ES is bound to take some notice from this. 
Иван Грозный:HI GENERALN20, I hope you remember me, lol.
Hahaha. Of course Ivan, I remember you. Glad to see you again. 
Fellow:but the mongols empire was finished long before the 1500s. The inka thrived through the 1500's
That's true. As cool as it would be to have the Mongols in the game, the greatest extent for them at this point would be as minor tribes. The Mongol empire was done by this time (Not completely extinct, but done as a major world power). 