Companies like SERCO have been paying low rates for years but still have managed to carry out their contracts. I remember Airworks paying peanuts but they still managed to recruit.
AirTanker may have to put up with a high turnover, but I'm sure that they will find takers for the jobs on offer.
Besides, with the RAF having hardly any aircraft left, they won't be visiting those nasty places that often, so maybe not that bad a life after all.