The secretary of revenue may appoint attorneys for the department of revenue and its divisions and officers, except attorneys for the state board of tax appeals and the division and director of alcoholic beverage control. All attorneys appointed under this section shall be subject to assignment and reassignment of duty within the department of revenue as may be determined by the attorney designated by the secretary of revenue as chief attorney of the department of revenue. Not more than three attorneys appointed under this section shall be in the classified service under the Kansas civil service act. All other attorneys, including the chief attorney of the department of revenue, appointed under this section shall be in the unclassified service under the Kansas civil service act and shall receive annual salaries fixed by the secretary of revenue and approved by the governor.