so do you have two umpire crews??
From what I have been able to find out, their version of a 4 man crew is 2 BU's and 2 PU's. The PU's work 2 different plates set in the middle of where the normal batter's box would be. Both teams are on the field at the same time and the teams rotate pitches from both pitchers who are standing on the mound at the same time.
Several people have had threads about travesty's of the game, I think this is one of them!!