At one point, Pepe, our trainer, had us all at once (about 20 teams) inspect 3 rows of chairs with each handler/dog teams roughly 4 feet away from each other so as to accustom our dogs (and us) to do searches in tight quarters with other teams.  We were trying to simulate an inspection of movie theater with several teams collaborating with the inspection.
That was a major challenge to most of us.  But it was awesome!