[narwan]

Tactical retreats should be done 'leap-frogging'. The units pulling back should pass by others further back who are holding their position. Since they haven't moved, they can shoot with max accuracy at anything following up the pull back.The units pulled back can now redeploy behind the covering units giving them similar protection.

This is another reason for keeping a mobile reserve force, to allow you to set up a blocking position through which the frontline units can pull back.