And one thing well worth remembering. JCA is not JUST strike. The original FCBA requirement (which JCA emerged from as a joint effort with FOAS) included and still includes a requirement to provide a DCA capability for maritime AD, that's the Fleet (ie amphibs, strategic lift etc).
All the leaking of performance/OA data is doing nothing. Everyone accepts C is a more capable option than B. Orca's point 3 has it all - question the £2Bn conversion cost. It has to be "made up".