The charter may provide for the vesting and exercise of legislative power pertaining to any and all services and functions of any municipality or political subdivision, except school districts, in the part of the county outside incorporated cities; and it may provide, or authorize its governing body to provide, the terms upon which the county may contract with any municipality or political subdivision in the county and perform any of the services and functions of any such municipality or political subdivision.

The charter may provide for the vesting and exercise of legislative power pertaining to any and all services and functions of any municipality or political subdivision, except school districts, throughout the entire county within as well as outside incorporated municipalities; any such charter provision shall set forth the limits within which the municipalities may exercise the same power collaterally and coextensively. When such a proposition is submitted to the voters of the county the ballot shall contain a clear definition of the power, function or service to be performed and the method by which it will be financed.