In order to provide orderly transition from the Los Angeles Metropolitan Transit Authority (herein sometimes referred to as “authority”) to the district, it may be desirable for a member or members or former member or members of the authority to serve or continue to serve as a member or members of the board of directors of the district and nothing in this part shall prevent each one of the three appointing bodies from each appointing a member or members of the authority as a member or members of the board of directors of the district if the appointing body involved, in its discretion, wishes so to do.