Hey guys, there's no reason why you can't put a colonial TW and a napoleonic TW as one game. In fact I think it shouldn't just be napoleonic or colonial total war, you can probably make the game between 1600-1900, with pikes and muskets available in early and gatling guns and repeating rifles and such for late. It should make for good city development as well, and you can include the entire world, including east asia. United States can pop out like Mongols do in M2TW around 1776, or as a rebel faction

As far as making a WWI or WWII TW, you probably literally have to have the processing power of the starship enterprise to even play a 1 on 1 custom battle. And all those complaints about not maintaining cohesion chasing routers, think about what will happen if you made a WWII infantry battalion do that in game, they'd be all over europe in no time lol.