Given I haven't actually used this army yet, I don't really feel equipped to offer any sort of tactical advice. Obviously my intent for infantry units is to pour arrow fire into the enemy as I advance and charge/countercharge with Free Companies. The real hitting power of the army is in the Knights (appropriately), so the function of the infantry is mainly to hold up enemy units so I can hit them from the flank or rear. And what better to keep the enemy tied up than a block of crazed religious zealots?