Heck, if we all cast Magic Stone and just pelted a guard, there's a good chance we could kill him at range- especially considering we could make enough to hand some off to the non-clerics, meaning that suddenly everyone is throwing rocks that do 1d6+1 damage at the guard, then as soon as he's dead I can mage hand the keys over and let us out. If we're lucky we could even put him down in the first volley before he could sound the alarm, and for an attack like that he WOULD be flat footed, no question.