Most of that argument is of course utter b8ll8cks. GR9 would only be of use in a cab-rank on-call CAS situation, where no-fly has morphed into no-drive armour at "civilians". CVS with a dozen or so would have been useful for that, but Kearsage is already there doing it. We could have had Ark or Lusty (if they weren't de-storing or in refit), moving a couple of weeks ago to do this (adding a bit of coercion to the effect), but not to be.
Nonetheless, T45 is not capable of providing Fleet AD alone. The only people who ever assumed this were the CS-types. No-one in Dark Blue was ever comfortable with it, but went along on the basis F35 ISD would be early-ish in the teens, NOT somewhere out towards 2020.