Quote Originally Posted by konny
Fighting phalanx archers don't do any damage when shooting on the front of the enemy. The best angle would be (appart from behind) shooting into the right flank of the enemy (no shields!). And for that they are best placed on your left wing. In EB Syrian and Cretian archers are also of some use in melee, so they can fall on the enemy's wing after spending all their missles.
and of course that's why cavalry was often used on the wings also - to chase down skirmishers, and generally secure the flanks more quickly.