The town manager may, with the approval of the board of commissioners, consolidate any two or more of the positions of town clerk, town tax collector, and town finance officer, or may assign the functions of any one or more of these positions to the holder or holders of any other of these positions. The town manager may also, with the approval of the board of commissioners himself perform all or any part of the functions of any of the named offices, in lieu of appointing other persons to perform the same.