I set my characters to all follow someone else, ie, char 1 follows char 2 who follows char 3 and so on. I wrote a macro that clicks PetActionButton1 and 2 (or is charge 3? regardless, the melee attack and the charge) and sets follow, so I just hit that macro and 4, and everyone follows and keeps shields up. Its not fool proof, but everyone generally keeps enough distance to charge, and if they don't charge they still swing. Just run back and forth over your target, generally a few seconds before turning around, and they should go down.