"If you look at the best run businesses, they are often composed of people with variable backgrounds - people that approach problems from different perspectives."
At first I thought this was satire. You'll excuse me if I take this in a more interesting direction.
Cited studies are not the first and last word on anything, especially when the question is "are scientists better than everyone else?"
Cited studies promote all kinds of false or questionable beliefs, particularly on political issues. As far as finding a study that answers the specific question "are diverse businesses better run?", I promise you won't have to look very far or very hard.
A common sense, thoughtful argument, backed up by information, trumps studies every time. And, surprisingly, an error-prone poll of a population of average intelligence trumps an intellectual's well-thought-out argument---this is why we have polling stations instead of a politburo.
There is a relatively established method though of creating boards of directors and/or leadership "teams" to achieve better decision making patterns; for this exact reason.
The group is more often than not a better performer than the individual.
Do you have cited studies to back this up?