They also serve...
Much as I would love to see the mighty Nicholas Soames (late of the 11th Hussars) returned to the Defence Office I'm not sure that military experience is a pre-requisite for the role. Obviously, post-war British politics was awash with military experience. Conscription and a World War will do that. But prior to that, arguably the two most influential Secretaries of State for War (none of that namby-pamby 'Defence' in those days) were entirely without military experience or even apparent interest in the military.
Edward Cardwell is probably forgotten now, but it was his Army Reforms that formed the foundation stone of the modern British Army, doing away with the purchasing of commissions and establishing a modern system of recruitment (incidentally, ignore the FOAK's claim that Cardwell was 'a former soldier' - he was a relentlessly civilian barrister and career politician).
Equally far-reaching changes were instituted at the beginning of the 20th century by Liberal politician, philosopher and lawyer Richard Haldane. An Expeditionary Force was established, the Territorial Army was founded, a separate General Staff was created for the first time and the entire system of training and tactics was overhauled.
Neither of these men had a military background. Would Alex suggest that the Duke of Cambridge - far more experienced and interested in the military than Cardwell - would have been a better Secretary of State than Cardwell, or that Field Marshall Kitchener was better than Haldane?
After all, Peter Tapsell was in the army - should we dust him off and give him the gig?