No exact answers exist but probabilities are very real. 3 people being simultaneously not fit for the job is quite unlikely. You have a choice here. Either 1

No exact answers exist but probabilities are very real. 3 people being simultaneously not fit for the job is quite unlikely. You have a choice here. Either 1 person is unfit for the job or 3 people. 1 person being unfit though not for sure is Far more likely. By one person I mean the manager is not fit. But in these cases usually the manager side steps the numbers and thinks he's doing the right thing.