Doesn’t this seem like the common practice in high-pension systems? You don’t use the overtime in pension calculations so it’s way cheaper to hire P people and run them on a 2x duty cycle than it is to hire 2P people and run them on a 1x duty cycle because the post retirement cost is Q in the first and 2Q in the latter.

You can’t account for overtime in pensions because the employees will conspire to force overtime for retiring employees to bounce the pension up. Just a natural risk with an entity that can’t go bankrupt hiring people.