Spec aircrew is a bit of a vexed issue, that's for sure.
Agree wholeheartedly.
I think the whole - "post 'em out after two years" thing is the main issue and is out of date.
It takes 2-3 years to get a pilot to the level you want in the Squadron (competent, maybe a route checker/IRE/QFI/etc) and then, you send em' away!
Generally speaking, it would make better economics and would retain the corporate knowledge, if tours were around 4 years. Reckon people would be happier, too.
But, then who does the crappy desk jobs for 4 years?? Never an easy solution...