A multichurch district board: Helping or hurting?

What exactly is a multichurch district council or board? A multi-church district is an amalgamation of several local churches in a given geographical territory under the guidance of a single pastor with associates, if any. The highest decision-making body for a district is referred to as a multichurch district council. What kind of relationship do these councils have to the local church boards? Do they replace them? Is there a duplication of functions? Is there conflict?