(1) The classified civil service and provisions of this chapter shall include all deputy sheriffs and other employees of the office of sheriff in each county except the county sheriff in every county and an additional number of positions, designated the unclassified service, determined as follows:
(3) In counties with a sheriff's department that operates the 911 emergency communications system, in addition to the unclassified positions authorized in subsections (1), (2), and (4) of this section, the sheriff may designate one unclassified position for the 911 emergency communications system.
(4) In addition to the unclassified positions authorized in this section, the county legislative authority of any county with a population of five hundred thousand or more operating under a home rule charter may designate unclassified positions of administrative responsibility not to exceed twenty positions.