(1) The composition of an appropriate unit in a health care facility, for purposes of this law, may be determined by mutual consent between such facility and the employees thereof.
(2) In the event no such mutual consent is available, then either the facility or representatives of employees may apply to the board and said board, through a duly designated agent, shall make a determination of the composition of such an appropriate unit.
(3) In determining such appropriate unit, professional employees may not be included in the same unit with nonprofessional employees unless a majority of professional employees in a proposed unit desire such inclusion. Weight shall be accorded similarity of duties, licensure, and conditions of employment, among other relevant factors, in determining an appropriate unit.