Save tank spawn points and use tanks to shield your base. Tanks shoot all and start moving after spawning. If you don't want tanks moving, spawn the tank in a limited area with walls or similar structure.
Permissions
This plugin uses the permission system. To assign a permission, use oxide.grant <user or group> <name or steam id> <permission>. To remove a permission, use oxide.revoke <user or group> <name or steam id> <permission>.