I thought at first I had read it wrong.
I didn't.
Then I thought, "alright, maybe it's a scheduling error?"
But as I examined it, it looked deliberate.
So if it was deliberate, the obvious conclusion:
They did schedule 4, but one or two of the guards would get to go home earlier than the listed time.
Since, after all.
Four guards would be complete, total, absolute overkill, right?
...WRONG.