Unless a county board has elected to exclude any or all positions otherwise subject to merit systems established pursuant to sections 12.22, subdivision 3, 256.012, and 387.31 to 387.45, from the jurisdiction of the personnel department, the provisions of sections 12.22, subdivision 3, 256.012, and 387.31 to 387.45 and any rules promulgated pursuant to those sections shall be superseded insofar as they are inconsistent with sections 375.66 to 375.71, but no positions subject to merit systems established pursuant to sections 12.22, subdivision 3, and 256.012, shall be removed from existing merit system coverage and placed under a personnel department established pursuant to sections 375.56 to 375.71, until that personnel department is certified in accordance with the United States Office of Personnel Management’s standards for a merit system of personnel administration. Nothing in section 387.43, shall be construed to prohibit the inclusion of sheriff’s department personnel in a personnel system established pursuant to sections 375.56 to 375.69.