In your example the assumptions you make seem to be along the lines that there is a fixed workforce. New candidates enter the market every year. Assuming that t

In your example the assumptions you make seem to be along the lines that there is a fixed workforce. New candidates enter the market every year. Assuming that the collective whole of graduating seniors from the universities are normally distributed in ability, you are always going to hire a group of people who ultimately will flesh out your bottom 10% even if it is not readily apparent in their first few years of employment.