Wondering about that myself anon.
POTUS picked him for a reason. He was sidelined by Obongo, played along for the ride.
https://foreignpolicy.com/2013/01/18/the-obama-administrations-inexplicable-mishandling-of-marine-gen-james-mattis-2/
Think it's part of the show. He seems like /ourguy/ unless something we don't know about.