At this level, I would tell the coaches to cool it right off the bat, even before the game. This isn't the NBA.
Tell them you are all they've got and if you hear any crap from them they can ref the game themselves. They should be setting an example of sportsmanship for the kids and not worrying about calls.
Do you get paid for this? If not, tell them you'll coach their team and they can take the abuse.
Sorry, my annual rec league stint is about to start.
