If the enemies are stupid (unintelligent animals, bloodthirsty savages, etc.) then a really good move is to have the tank charge forward on round 1 and then Dodge. The enemies will "focus fire" on him and waste their attacks, likely wasting more damage than the tank would have output against them had he attacked. You get bonus points if your tank is a raging barbarian so even if she gets hit she's resistant to the damage. Extra double bonus points if the tank has some ability that lets them attack as an action!