(1) At the time designated in said notice, the county commissioners shall proceed to hear said petition and the evidence for or against the same. Any registered elector of the county affected shall have the right to appear and be heard upon said petition, subject, however, to the right of the county commissioners to limit cumulative testimony and to prevent the undue prolonging of said hearing.
(2) Within 5 days after the date set for said hearing, the board or boards of county commissioners shall make such order in relation to the consolidation of said offices as they shall deem proper. Such order must be made at least 7 days before the date on which declarations for nomination may first be filed for any county office.