Insurers may agree to the equitable apportionment among them of insurance to be afforded applicants who are in good faith entitled to but who are unable to procure such insurance through ordinary methods. Such insurers may agree on the use of policy forms, rating systems, and reasonable modifications thereof for such insurance. Such agreements may include pooling arrangements or reinsurance. Such agreements, policy forms, rating systems, and modifications thereof shall be subject to the approval of the director.