The first level billmen also have very low armor so don't stand very long head to head, however they make exellent flankers. They have weapons that are effective against armor so can eat them alive. Armored Billmen have better armor so can take a frontal attack better but I still prefer Sword & shield troops for the Anti-spear/Infantry work. So generally speaking use them on the flanks or rear of armored opponets for maximum effectiveness!