Lose control and Gain your sanity
From my experience, when you are taking three (or more) children out, excessive control is not necessarily a good thing (for your own health). Tight control typically means more shouting, more stress and lots of anxiety.
So my suggestion is less control. Safety and kidnapping aside, kids just generally want to have fun and get dirty. And if you're alright with some noise, chocolate stains and grubby faces, then go with it and let them go wild. Sit back, watch the action and let the other adults tear their hair follicles out.