If we're all supposed to be doing a synchronized surprise attack, wouldn't it make sense to let everyone get their initial attack in before letting the guards get their reaction? Especially when the guards' move would take as long as you've described? The scene was set up for all the heroes to attack at once, but with your response you're essentially saying that Wasp, Spitfire, and Quasar would just sit there doing nothing for upwards of like 5-10 seconds while Superbus fights by herself and the guards call for back up.