The introduction of these posts is a political one. As elected officials, if the public are unhappy with the performance of their local force they can lose their jobs. Theoretically this gives the public more of a say in prioritising the areas/types of policing in their areas.
Will it work? - Not everything that happens across the herring pond is as functional here. Personally I think a National Police Service is the way to go; this is happening by default in some areas where constabularies are combining/co-operating with their resources.