Don't be so sure that it's that difficult to go from a 4 man to a 2 man flight deck. Whilst the old herc may be a little less complex than, say, the VC10 is, the J is as complex, if not more so in some ways, than a modern civvy flightdeck. The only people that struggle on a 2 man flightdeck are those that were able to hide their lack of ability in the crowd of a 4 man flightdeck.
99.9% of people leaving the RAF to go civvy have no problem converting across to the civvy 2 man flightdeck.