The plan to move Sultan has fallen on it's backside because the Navy have no desire to intergrate their training with the other two services. Collingwood's been a case study for that for years.
You do know what training is undertaken at Collingrad, don't you? Perhaps you could expand on how ASMD, ASW, ASuW and EW tactical training and the ops room and bridge trainers could be economically delivered elsewhere? Whereas clearly the RAF has no such problems, as long as there's a runway and hangar...
The Sultan move economics were always predicated on being able to get a significant pile of bunce from redeveloping the site for housing. Trouble is that the infrastructure in Gosport/Fareham won't support that level of additional housing, so planning permission (and hence realisable value) is unlikely. Add to that the lessons learned in retention over the last few years and it becomes clear that the perceived benefits of tri-service collocation may not be all they're cracked up to be.