BACK FROM MY DAYS as a defense contractor, I recall this quip on the proper use of military personnel:

Military personnel can be divided into four categories: brilliant and lazy, brilliant and industrious; stupid and lazy; and stupid and industrious.

The brilliant and lazy should become the Commander’s staff; the brilliant and industrious, field commanders; the stupid and lazy, infantrymen. The stupid and industrious are worthless and should be discarded.

President Obama found a use for the latter; he made them Cabinet officers.