We have two data centres with a fibre link between the two.
90% of our workstations would connect to these two sites.
This would cover over 5000 devices.

We have 3 WAN sites with radio links with about 200 desktops
across the 3 of them.

Does one need a seperate zone for each WAN site and would one
then need a primary server in each zone with its own SQL database.
Can multiple zones use the same database as the one for the data centre or
must each zone have its one database and management server.