Did Not Understand the Planning on the Fake "Crime Scene" (SPOILERS)
Might of missed something but the boss did not want to have his captives in the green room suffer gunshot wounds. Since authorities might suspect that corpses supposedly killed by dogs might be suspicious if also shot up and full of lead. So the boss tells his men to use machetes to kill them then let the dogs gnaw on the corpses as if though the machete wounds would not be noticeable to a medical examiner or two. Dunno, I'm probably jaded from watching too much CSI.
He killed sixteen Czechoslovakians. Guy was an interior decorator.