It is a mess.
It starts with the desire to replace the Canberra with this all singing and dancing GOR.339.
Scale of numbers being large.
Progressively as costs rise, the numbers get scaled back and ultimately it seems to dissolve into 50 F111K for EoS and a larger number of AFVG for European Theatre.
The P1154 MRI numbers closely matches the later Jaguar.
Interim we get 70 F4K (late and to the FAA's surprise) or about just under half the desired P1154/Jaguar figure.
Harrier never could deliver MRI.
CAS yes and BAI and at a stretch SRI.
Fine as a Hunter GR successor and more flexible in basing than anything else.
At least it was cleared to deliver tactical WE.177
The TSR2 wasn't simply a replacement for Canberra, it was also a replacement for the V-Bombers but this isn't often talked about. The Buccaneer replaced a Victor and a Vulcan sqn which had been stood down and earmarked for the TSR2/F111K, and the Vulcan squadrons lingered in service longer than expected waiting for the Tornado to replace them. If the 193 TSR2 or thereabouts had been built they would have replaced the 6 Canberra squadrons that ITOL were replaced by the Phantom/Buccaneer/Harrier and the 9 V-bomber squadrons that ITOL were replaced by Buccaneer/Tornado. I don't think the TSR2 is all-singing/all-dancing, it was an increment better than the likes for the A5C Vigilante, Mirage IV and F4C that the RAAF looed at in late 1963, as it should be for a plane then expected to be in service in 1969, but otherwise an perfectly conventional aircraft.
As for the Hunter replacement, there was the NMBR3a and 3b; the 3b was a subsonic VTOL attack aircraft perfectly suited to the already developed P1127. The 3a was all-singing/all-dancing supersonic VTOL fighter. The Harrier could have been put forward as NBMR3b and put into RAAF service to replace the 6 Hunter squadrons that IOTL were replaced by Phantom/Harrier/Buccaneer. With the TSR2 able to do so much the low performance of the Harrier will be accepted as the cost of such flexibility. This would leave the Jaguar as a trainer, or perhaps to wither on the vine like the AFVG and the Hawk still be developed.
This leaves the RN Sea Vixen replacement, which on the face of it looks pretty bad. However with the arrival into service of the Jaguar in about 1974 Phantoms which had replaced Canberras and Hunters were re-roled and replaced Lightnings in the Air to Air role. Ideally someone with clout in the MoD could make the decision that the Sea Vixen replacement in the late 60s could also be the Lightning replacement of the early 70s. This would equal about 10 squadrons, and could be akin to OTL Phantom.
This would leave Britain with a High programme - TSR2, low programme - P1127, shared programmes F4K/M and Jaguar.