A fire protection district resulting from the merger of two or more fire protection districts located in the same county shall be identified by the name of the county and the number of the merger fire protection district. However, the fire protection district resulting from such a merger shall be identified by the number of the merging district or one of the merging districts if a resolution providing for this number change is adopted by the board of fire commissioners of the district resulting from the merger or if resolutions providing for this number change are adopted by each of the boards of fire commissioners of the districts proposed to be merged.