It's done at nearly every competition site out there, unless teams cook them on separate cookers. There's absolutely no reason not to cook em at the same time.
Go for it!
Big JT's Smokin' BBQ Competition Team
"The path was worn and slippery. My foot slipped from underneath me, knocking the other out of the way, but I recovered and said to myself, 'It's a slip and not a fall.'"