Pheasant - you are correct that JF Harrier was a bit of a disaster and most would admit that it was due to the RN's inability to keep up their end of the deal, in particualr supply half of the manpower. I think the RN have learnt their lesson - it almost led to the disappearance of the FAA and I don't think they will repeat it for JSF.
J Helicopter F, by contrast has worked out pretty well, despite the inevitable early frictions, with a Land focus but even some AAC types admitting that the RAF does some things pretty well!
Jointery really is the way ahead in many areas, although I agree that we have a hard job convincing the army that it isn't spelt A R M Y.