Cooperation among rating organizations or among rating organizations and insurers in rate making or in other matters within the scope of this chapter is hereby authorized, providing the filings resulting from such cooperation are subject to all the provisions of this chapter which are applicable to filings generally. The director may review such cooperative activities and practices and if, after a hearing, he finds that any such activity or practice is unfair or unreasonable or otherwise inconsistent with the provisions of law, he may issue a written order specifying in what respects such activity or practice is unfair or unreasonable or otherwise inconsistent with the provisions of law, and requiring the discontinuance of such activity or practice.