Isn't it more correct that actually the RN were in need of a attack capability the SHAR couldn't give them, so came up with the JFH concept to ensure they had a future? (and of course, two shiny new boats?)
You have to admit that the senior RN chappies were extremely clever in getting the concept in place before SDR so that it dovetailed nicely with the budget restrictions. (Sorry - that supposed to be 'capability requirements'.....!)