The metro council has to doles out the money that the department runs on each year. If they say you only get 5 political spots paid for, then you only get 5. The chief doesn't actually decide how any of the money is spent. There are also permanent laws that define the position of chief and the department. They can make them whatever they want. If in 2018 Greg Fischer is Mayor, the investigation is a whitewash and the councilpeople are unhappy, I wouldn't count out a mandated restructuring to fix