The secretary of revenue may organize the department of revenue in the manner he or she deems most efficient, so long as the same is not in conflict with law. Division heads shall perform such duties and exercise such powers as the secretary of revenue may prescribe and such duties and powers as are prescribed by law. Division heads shall act for, and exercise the powers of, the secretary of revenue to the extent authority to do so is delegated by the secretary of revenue to the division head. Personnel of each division shall perform such duties and exercise such powers as the head of the division may prescribe and such duties and powers as are prescribed by law. Personnel of each division shall act for and exercise the powers of, their division head to the extent authority to do so is delegated by the division head.