The commissioner shall, with the advice and approval of the State Board of Agriculture and Industries, organize the Department of Agriculture and Industries into such divisions as deemed necessary to properly segregate and conduct the work of the department. The commissioner may assign to each of the employees of the department such powers, duties, and labors as the commissioner may see fit. At the discretion of the commissioner, one additional person for each division may be employed in the unclassified service. Provided, however, the total number of additional persons who may be employed in the unclassified service under the provisions of the preceding sentence shall not exceed three additional persons.