Thank you very much for your reply.
The reason two gateways have the same IP address is because of the customer's network environment. (I don't want this configuration.)
I plan to place one management server in the main center and one management server in the backup center and configure HA for these two management servers.
And this HA management server tries to manage the firewalls deployed in each center (main center, backup center). But these two firewalls have the same IP address. The goal is to install the same daily updated security policy on each firewall of both centers.
Each firewall in these two centers will always have the same security policy.
Therefore, even if a failure occurs in the main center, the backup center firewall will be able to enforce the latest security policy.
This is the configuration my customers want.
Are there any other configuration options that could solve the customer's needs?