§ 13. The chief of staff of the state. There shall be a chief of staff of the state who shall serve as such at the pleasure of the governor. The chief of staff of the state shall be appointed by the governor and while holding such title shall have the grade of a general officer. The powers, functions and duties of the chief of staff of the state shall be those prescribed by this chapter and by regulations issued pursuant to this chapter. All such powers, functions and duties, however, as well as those which are or may be imposed upon the chief of staff of the state by the laws and regulations of the United States shall be exercised and performed by him under the direction and control of the adjutant general.