Light infantry dodging everything

Hey there! Great question. First, historically, a careful, fast-moving loose-mounted light infantry unit could destroy a heavy infantry unit by peppering it with hit-and-run attacks. The Battle of Lechaeum is a famous instance of this, one that that taught the Greeks that they had to increase the proportion of light infantry in their armies. See http://en.wikipedia.org/wiki/Battle_of_Lechaeum Many battles featuring heavy troops against horse archers demonstrated similar outcomes. In terms of game mechanics, several factors make it difficult for a unit to actually do this. 1) Units cannot withdraw if they are disordered. A unit which withdraws becomes disordered. Therefore you can never withdraw from two consecutive attacks. 2) Units can only withdraw up to their marching movement. For light infantry, that is only 2 hexes. Heavy infantry can charge 3-4 hexes. For horse archers, that is 4 hexes. Sword-armed heavy infantry can charge 4 hexes, and heavy cavalry can charge 9 hexes. Thus it is impossible to withdraw outside of charge range without having blocking troops. 3) A heavy unit under fire from a light unit can defend in lieu of attacking (+2 to +4 AC), giving it a likely AC of 6 to 10. The light unit will hit on between 5% and 20% of its attacks, while depleting itself of ammo on 5% of its attacks. Before it destroys the heavy unit, it will likely run out of ammo. So if you're playing a heavy force against a light force, you have two basic strategies. Either you can hunker down, wait for the enemy to get depleted, and then fight them in melee (where they will lose); or you can attempt to whittle down their force by disordering them, and hitting them again while disordered, either with good troop placement or lucky initiative rolls.