I recall the "admin discharge after 3 failed attempts" rule was brought in with the RAFFT just over a year ago.
Aside from my observation above, if it is thought that RAF personnel are likely to need the physical skills imparted by these drills, then my former colleagues in light blue are really up sh!t creek.
Army = Shooting and running around
Navy = Driving and fixing boats
Air Force = Driving and fixing planes
Incidentally, I am willing to bet that no one has yet been subject to an attempted admin discharge related to the RAFFT under the current system, whether successful or otherwise. Also, the more rigourous the system, the more personnel will obtain medical exemptions for the aches and pains many people have picked up, particularly for knee and joint complaints.