Trump will not be able to fire Noem, Bondi, or Lutnick over incompetence or scandals (I suppose if bulletproof evidence could be found but that almost does not exist in the misinformation age). He chose them for loyalty not competence. If they remain loyal, he won't get rid of them. If he does, he has nothing left. He taught competent people (John Kelly, Mattis, Tillerson etc) to avoid him like the plague. All he has left are the loyalists.