TJ
What you say is correct. They would have done well to research the subject and quote the criticism of the PAC when, about 6 years ago, the figure was "only" £300M or so. The expenditure is indeed increasing.
But such an article needs to ask why FATS, in its present form, is needed in the first place. From a personal perspective, it started when the Chief Engineer (AMSO) issued an edict in 1991 that henceforth all admin grades would be regarded as senior to engineers. A young lady 3 grades below me was appointed as my line manager, much to her horror.
This extended into MoD(PE) by 1996, when CDP ruled he did not want engineers managing engineering projects.
By 2002 I was bollocked by bosses at AbbeyWood for failing to spend a penny of my multi-million annual "extramural assistance" funding. My explanation that the work was what I regarded as a basic competence for a 3rd year apprentice and I was actually unhappy at the level of grade I had to delegate it to cut no ice. It simply would not do to have a very capable engineer working for me who could do the job. He was to be got rid of and I was to employ consultants. (I didn't). What really annoyed them was the fact the bar was being raised, when policy was to lower it to justify the consultants - hence FATS, which is a laughable concept to anyone over about 60 who has ever worked in MoD. I know who I wanted to get rid of, and it wasn't the guy whose salary of less than £25k saved MoD over £4M, year on year.
Within the same domain, some very capable and highly qualified engineers routinely adjusted their CVs to remove this unwanted attribute. This was when the pass rate for engineers on promotion was in single figures, but over 80% for admin. Bearing in mind that an (avionic) engineer had to be able to do all the admin jobs at the same grade, but not vice versa.