Yes a 5 year training pipeline with a 5 year decision cycle is not going to be easy to manage. Some would say it is madness.
I also meant to add that we have quite a retention issue outside of cockpits/flightdecks. We always had a requirement for aircrew in non-flying roles but the advent of the DH structure increased the requirement just at the point that we hoped that the requirement would reduce. It's quite hard to get multiple ground tours out of aircrew for some unfathomable reason…