Arkady
You selectively mis-quoted and missed out the 'Best guess' bit. The time scale quoted was from Big Al himself. There are currently no ex-mil Area ATCO's in the LACC system, although there are a couple of ex-mil aerodrome (and an ex-LJAO at Hurn, although a baby will slow her entry to LACC). This 'fast-track' course is specifically for ex-mil who were LJAO controllers, therefore familiar with London airspace and indeed both candidates are familiar with the LACC HMI. It will indeed be interesting to see how quickly they validate (if they get that far).
At the risk of a 'flaming' I would point out that mil ATCO's are used to moving from unit to unit and are very flexible and adaptable of necessity. I believe that their civil cousins tend to stay put and have that mindset, so moving elsewhere is a 'big thing' and not 'usual'.