In St. Mary’s County, licensed registered school nurses, Junior Reserve Officers’ Training Corps (JROTC) teachers, and supervisory noncertificated employees of the public school employer shall be included in the unit. There may not be more than two units in a county. In Baltimore County, one of the units shall consist of employees who are administrative and supervisory certificated employees. The second unit shall consist of all other public school employees as defined under § 6–401(e)(1) and (3) of this subtitle. All eligible public school employees shall: Be included in one of these units; and Have the rights granted in this subtitle and Title 22 of the State Government Article.