I hope who ever Trump picks can manage the State Dept, a goofy bureaucracy stuffed full of democrats, know-it-alls, and peaceniks. They all have snivel service protection against firing. Many of them are scattered all over the world where it is harder to keep track of, and ride herd on them. Flinty old John Bolton might be able to handle them, but I'm doubtful of Romney, Guiliani, and Corker. Petraeius might be tough enough.
As it is, a lot of 'em are getting ready make leaks embarrassing to the incoming Trump administration, and the MSM are sitting up, wagging heir tails, and begging for some dirt to print.
Although the secretary of state cannot fire them, he could announce a policy of unaccompanied overseas tours in unpleasant places for State Dept leakers.