Talking with two event promoters, they indicated that the staff you get invariably prove challenging... Their recommendations:
Things I'd try:
Meet with facilities management as soon as possible. Make sure you have facilities on-hand for the show.
Everyone gets your cell phone number.
Give the staff the list of jobs ahead of time.
Ask them who wants to be leaders for the day.
Let them select which jobs they want when they show up. Leaders get first pick. Rock Paper Scissors for any ties.
Make the leaders escalation points, all questions go first to them, then to you.
Do as much as work ahead of time as possible.