Currently, Defense, Attorney General, Interior, UN Ambassador and Chief of Staff are acting.
There are many benefits for Trump:
- As Trump recently explained, he knows more than most of his generals (Mattis) and secretaries (Tillerson). He also essentially runs the government from the White House, his ad hoc press briefings (shouted questions, etc.) and his Twitter feed.
- He avoids the Senate confirmation process on most of them, eliminating the Article One oversight.
- “Acting” makes it easier to fire them and it will produce less criticism.