Art identifies the problem that so many identified 3 & 4 years ago, but which were ignored by those who "knew better", but who had never operated in, or with, Air Support at the sharp end.
Sid, I understand that the numbers maybe skewed a little by the two 135 spares not likely to be available for some while? From what I read, and as soon as the upgrade programme starts, one will be at Staverton for upgrade (total programme likely to run for well over a year?) and the other unavailable as a spare, if it's being used at Boreham.
It all rather knocks the "spare" aircraft plans into a cocked hat, and therefore the country coverage. Being a little less precious about county borders in the past, within a region, proved to be a much more mature, flexible & easier to manage option, even if it was unlikely to have remained financially viable in its entirety.