The governor is empowered to appoint two (2) persons to be known as administrative assistants, to aid the governor in the performance of additional duties of the office. These administrative assistants shall hold office at the pleasure of the governor and perform such duties as may be delegated to them by executive order of the governor or otherwise. An administrative assistant may also be the head of a department of the state government; provided, that the administrative assistant's total salary shall be fixed commensurate with the services rendered.