The county commission may, from time to time, pursuant to the provisions of section 161.152, submit to the state board of education specific plans for the reorganization of school districts of the state. Each plan shall be in writing and shall include charts, maps and statistical information necessary to document properly the plan for the proposed reorganized districts and to provide a comparison of existing districts with proposed reorganized districts. In recommending prepared reorganization plans, the county commission may divide all existing unreorganized districts and any reorganized district not offering an approved program of work through the twelfth grade if division is in the best interests of the children, and place any portion in any proposed district, but each proposed district shall be composed of contiguous territory.