There is obviously a problem or they wouldn't need a 'solution'.
Wouldnt it have been nicer to offer (and be more productive), say a $40000 retention bonus for the guys who remain for say 2 years after the upgrade and a further bonus every X years. Enhances retention and drives recruitment as opposed to pushing NAC FO's to leave before command, and further erodes T&C so as to reduce future recruitment.
I guess that's too much carrot and not enough stick though.......