I played 4 Generations by riding arabian, and 5 Generations as 2h. From my feeling, if we really need to nerf something (in current situation, I really suggest to stop nerf anything), I prefer to nerf 2h first, not the arabian and cav. Riding arabian needs your high control tech. You need to precise control when to stop, when to jump, when to turn, which targets you may attack or not. As long as there is a little control error, arabian will be killed and you will fall down, as arabian has so poor hit points. The tech for control horse is same as the tech for control blocking. I can't understand "why so many people may only accept good blocking tech persons, but can't accept the persons with good horse control tech?!"
In the end, don't forget, all cav have much higher upkeep than infantries.