That's because you work for a non-UK company, TT!
There are quite a few folk around - particularly those who PVR'd - who haven't a clue what their recall or call-out liabilities are under the Reserve Forces Act. That never used to matter - until Bliar's government called-out non-volunteer reservists for GW2. The first time that'd happened since Suez in 1956.....
The increasing reliance on an increasingly reluctant number of reservists is yet another of those crazy MoD decisions which will soon come home to roost. 'Total Force'.......or total farce?
As for 9 plus 6 A330Ks - well, just hope that they don't need to be in 2 places at once.
24 x A310MRTT would have been a much, much better option. Too late now though. OK - 71 tonne of fuel rather than 111 tonne, but at one stage they would have been available for 1/3 of the cost.
I cannot imagine anyone being daft enough to want to be a mercenary on the FSTA - unless the fringe terms are pretty spanking good!