Here's the strategy - when the enemy is advancing on you and you kill one of them, the unit keeps advancing, they go back and pick up their dead later. If, however, you only wound one of the enemy then it takes two members of the enemy force to provide aid and evacuate the wounded soldier.
So the math is, kill a soldier and you've removed one from the battle but wound a soldier and you've taken three out of the battle.
Caption this Meme
