I’ve read that one reason Trump hasn’t nominated anyone for 515 out of the 549 positions which need Senate confirmation is that he thinks they don’t need so many people. Back during the campaign, he resisted hiring the usual large staff, and got away with it largely due to getting $1 Billion in free airtime, as well as a disturbingly large number of Americans being really stupid and gullible.
I suspect his thinking on staffing the Executive Branch is similar - they don’t really need that many people, and after all, he turned out to be right about the campaign staff thing, right? But I’m pretty sure that the Government functions can’t be covered by free airtime and stupid, gullible Americans.