A lot of the males aren't good players with other dogs just because they are so Alpha. But his dogs I've seen playing with others. ~His~ sport dogs aren't aggressive. The bite work is a game. In those videos you'll see them working bite work ON Wayne. It's just a game with a guy in a bite suit. They'll play with the teasers after the game is over.
It's funny because when they've done well, the dog 'wins' the bite arm. I (joking) asked him if the police dogs he's sold ever are disappointed when the arm of the bad guy doesn't just come off. He said with a straight face "sometimes it does" ;~D
It was a joke, of course ;~D