I believe that diverse teams can out perform conforming teams in most instances but some level of conformity is needed for teams to function at a high level.
If almost everyone on a team does not have a spoken language in common then the communication challenges will be enormous.
I have worked on projects with all white males all about the same age and we were very high performing. We were not innovating we were producing and we were operating to conventions that were well established by others just like ourselves. We understood the conventions and how to execute. We could hand a task over at the end of a shift without hardly the need for discussion, we just knew what to do and status communication was brief while still comprehensive. I have worked with guys who would be ready to hand you the wrench you needed for the next task just as you were about to ask for it. I am not saying that wouldn’t happen with a diverse team but when you have similar background you tend to think alike and develop that rapport more quickly.
I think the military sometimes trains the diversity out of their diverse teams. Trains everyone to a new conforming culture.
Diversity has benefits but they do come with a price. Teams need to be designed for the job they are expected to accomplish. Many times you need many different points of view. I had one coworker who reviewed procedures back to front. Very unconventional but it was a good thing. Sometimes the back end of procedures got short shift in the review process because of time pressures or just boredom. Note, the emergency procedures were in the back of the document.
Warning, possibly sexist comment follows, often women reviewers would find spelling errors and grammatical errors that male reviewers missed. One think that I think diversity can tend to prevent is corruption, fraud and misbehavior. Group think can lead to some bad behavior.