The retention argument for a higher grade is a bizarre. It basically says to get ahead in public service you have to be bad at your job.

Low retention rates are due to: Weak recruitment and management policies and not pay-grade.
Good management and policies retain employees.
Bad management – employees leave (Harvard Business Review – Why People Quit)

My recommendation was to hire all employees at a lower grade and promote them only if successful. They start some new hires at higher grades and let them bill bill bill. Huh? Why are we wasting time and money?

There’s a major flaw in using retention as a reason for higher promotion potential because it penalizes strong supervisors and managers who can retain productive employees and rewards poor performers with higher pay.