HH,
So in the case of the RJ it was three years from which event to "flying in UK colours"? Was that mention in parliament, firm orders being placed, what?
Also in terms of the RJ, presumably the back up support systems for an aircraft conducting that role were largely carried over from the R1, so were already in place with manned and experienced staff. How many 51 Sqn aircrew were ready to convert, enough to man the whole fleet of RJs maybe.
Now look at a new MPA/MMA. How many trained, experienced support staff, with the right equipment are ready to go. How many trained and experienced aircrew are available, 20-30 maybe. There has already been a 5 year gap in UK MPA ops, and most (but not all) of the experienced UK MPA aircrew no longer wear a blue suit.
Comparisons between the R1 to RJ transition and the MR2 to ?? "capability gap" closure are not valid - in my opinion.