No such merger or consolidation shall go into effect until the plan and agreement therefor is filed with the director and approved by him after a hearing thereon. Such plan and agreement shall be approved by the director within a reasonable time unless he finds such plan or agreement:
(1) Is contrary to law; or
(2) Is inequitable to the policyholders of any domestic insurer involved; or
(3) Would substantially reduce the security of and service to be rendered to policyholders of the domestic insurer.