Cheexsta said:
Bear in mind that the Romans used cavalry in such a small proportion to their infantry that you'd literally have to have an army of 15k or so infantry before you even start adding cavalry units (300 cavalry to every 4-5k infantry), and near as I can tell, they're the only major faction without cavalry access - local or mercenary - at the start of the game.
You are incorrectly assuming that the integral cavalry fromation in later legions was the only cavalry in Roman armies. It wasn't. Auxilia cavalry was fromed in it's own "legions". And most Roman cavalry was auxilia, Gauls being the most numerous AFAIK.
Egypt and Armienia (!) are couple of countries that didn't have horses back in 1.1 at least. Haven't tried 1.2 so don't know if they changed province resources. I personally modded my game so that some provinces like Armenia, Cappadoccia, one province in Libya, one of the Carthaginian elephant provinces and the one in modern Lombardy have horses (gives either direct recruiting or mercenaries to all majors and mediums). I also eliminated most of the iron in Thracia, and gave it some horses. As Thracia was famed for it's light infantry and horsemen, I didn't really get why it got mostly iron.