Quite so,
There will never be a problem filling the right seat at RYR (for the foreseable future anyway), there is a line a mile long of starry eyed wanabees fresh out of Oxford or wherever willing to sell their soul to fly a B738, and it only takes RYR a couple of months or so to get them on line.
However, if significant numbers of 2500 hour + F/O's leave, plus some of the younger Capts who as you say,realise that another 30 years in the LHS with RYR is unsustainable, then I can see a problem, especially if the supply of suitable DECs dry up.
With a relatively high failure rate of command upgrades (rumoured to be over 40 %), its filling the LHS that's going to be a problem for them.
PS
You're right about them "wanting" to hang on to the older Capt's , the company has been a lot more accommodating towards me recently !!
