That's as maybe Duncs but I am not aware that this is true. All Grads get one rate all straight ins another.
How do you assess quality for a pay award? Assessment at OASC? Performance at IOT.
Problem with precise differential pay is that it is difficult to administer fairly and may also be divisive when the whole point of IOT is to meld individuals into selfless team players.
OK, that latter may rub off as you climb the greasy pole but that is the idea.