CG,
Unfortunately, the reality is that an Army CDS would join in with CGS to insist on the parochial view that more tanks and more infantry is what is needed, out trumping the single arguments of CAS arguing for more FJ sqns and CNS arguing for more submarines. The debate is there to be had on what is the right balance for the UK but independant defence analysts with pan Westminster input would hopefully listen to the defence chiefs but ultimately make an unbiased judgement on the path to follow - with a strategic plan out to 30 years agreed by all parties.