I would not call it corrupt. I see it more as a guard job is to keep the common day peace.
But don’t cops lay off work to contractors? The average cop is not going to go down to deal with rabid wolf that terrorizes people. No they send animal control.
Or how in western movies how they put bounties on infamous gangs?
Or private detectives chasing down hard solved crimes.
Or private security firms?
Why would that be different to lay of work to a group that are more suited for that kinda work?