The problem is not in the stats, nor the supposed capabilities of the billmen, it is in the animation, causing them not to attack. Checking over at twcenter.net forums, it is reported that stationary unit of cavalry were completely eating up English foot knights, billmen, Varangian guards, Norse axemen. If 1 stationary unit of cavarly can melee through 1 unit of English foot knights, it is most certainly not behaving properly.