I have found that as well. It works especially well with cavalry as they have an extra fast sword animation while they are riding through enemies and get off 3 or 4 hits to their normal 1. It also works well on the walls when your men are just sitting there slugging it out 5 or 6 units at a time exhausting themselves. Order them to run through the enemy, then attack.
I only use this when my unit is stronger than their foe, otherwise a lot of them get killed while they are moving into position.