If no one is doing unmonitored and disproportionate amounts of overtime, then the likelyhood of an incident is greatly reduced. Wouldn't you agree DFC? Even you have to concede that point.
As for training: As we have a core of dedicated training staff in the school along with some Operational ATCOs, then hiring retirees to train students frees up the ATCOs for Ops. When the trainees (DE or students) enter the Ops environment they will be assigned an OJTI (On the Job Training Instructor) and work parallel to that OJTI in a live environment with the "control" of the sector slowly being passed over from the OJTI to the trainee over a period of days, weeks or months. While this is happening the OJTI and his/her trainee are counted as 1 person available on the operational roster. When the trainee "checks out" they can perform on their own (with the possible exception of not allowing 2 newly rated people to sit in the same sector)
At no time in this process has the number of operational ATCOs decreased. In fact it is steadily rising, eroding the need for overtime.
If you are a pilot, do you want to be controlled by (A)someone who has worked 8 day shifts and 4 night shifts in the previous 14 days, or would you prefer (B) a well rested and mentaly fit controller whose hours are monitored so fatigue is removed from the equation?
A simple answer please, (A) or (B)