Well that’s true, but given the ME Obama mess and the fact that Trump is a military kind of guy, who was wanting to do clean up and clean out over there, it made sense he wanted theater expertise at the helm of Defense and the Pentagon. Imho.
It could well be argued that clean up and clean out of the defense department (which by the way is the one area Trump has looked to only add spending rather than look for waste and cuts) would actually best be done by someone who hasn’t spent his career in the department. That is really behind the traditional idea of civilian oversight at the top of defense.
And ugh, how about this—Trump hired McMaster on a half-hour interview based on McCain having recommended him to Trump. That right there is the tip off that McMaster should have been the last man in DC to name as NSA.