To employ, with the approval of the county board, such additional employees as are needed for the discharge of the duties of the office. The non-clerical employees shall be persons versed in the principles and methods of education, familiar with public school work, competent to visit schools, and licensed pursuant to this Code if their duties are comparable to those for which licensure is required by this Code.
     On and after July 1, 1994, the provisions of this Section shall have no application in any educational service region having a population of 2,000,000 or more inhabitants.