Under order of court, with or without notice, a fiduciary may engage, at estate expense, outside specialists, and may delegate to them, or consult with them for advice regarding the performance of aspects of the estate management which require professional skills or facilities which the fiduciary does not possess, or does not possess in sufficient degree, and the fiduciary may employ, at estate expense, subordinates and agents to perform ministerial acts and carry on or complete details of estate business under the policies and terms established by the fiduciary.