Each of the four zones has a different purpose and reason. Within each zone the districts will reflect each other and will rarely if ever conflict. These zones are sort of a pecking order within the city. If you have a business it goes into a certain zone in a certain district. Deviate form that and your business may be moved without your concent or shut down.
Zone 1
Waterfront District
Warehouse District
Entertainment District
Business District
Zone 2
Residential District
Temple District
Zone 3
Professional District
Guildhall District
Academy District
Park District
Zone 4
Civic District