I always use heavy cavalry in combination with longbowmen, a deadly combination. I'm not sure if that's an option for you Memnoch, since that would force you to be English.
And of course you don't have those type of units early in the game, so you'll have to improvise until the moment comes. Cavalry is my favourite choice anyway, so from early on my armies mostly consist out of hobilars, plus a few cohorts of spearmen to stop the enemies' cavalry. Hobilars don't have a very powerful charge however, so prepare to lose a battle or two, especially when your opponents are Arabic fighters on camels. Also important is to control all waterways surrounding your lands so you can drop armies whereever they are mostly needed.