I you don't have a lot of resources but want to win thoroughly, make a large number 
of archers (specialized archers, like Longbowmen and Hand cannoneers are best), a 
few monks, and some ranged siege weapons (either Mangonels, bombard cannons or 
trebuchets) and give them a common number. then put them in Line formation on either 
defensive stance or stand ground. The monks will heal your archers as they are hurt 
and the archers and siege weapons will destroy the enemies and their town. The longer
ranged your guys are, the better. Just watch out for enemy mangonels, as they will 
kill your guys like flies.