Any Missouri mutual insurance company operating under the provisions of sections 380.011 to 380.151 or any company operating under the provisions of sections 380.201 to 380.591 may convert to a mutual insurance company in the manner provided in sections 379.585 to 379.625; but, for purposes of conversion under the provisions of this section, the assent otherwise required by the provisions of section 379.605 for such conversion need not exceed seventy-five percent of the members voting thereon, both in person and by proxy, at a meeting called for that purpose.