All you need to know is this...primary will ALWAYS be primary and secondary will ALWAYS be secondary, unless they are rebuilt. Either way can be active or standby...so say primary can be standby and secondary can be active
scenarios:
primary-active ... secondary-standby
primary-standby ... secondary-active
secondary-active... primary-standby
secondary-standby-primary-active
Technically thats really 2, not 4 scenarios lol
Makes sense?
What is the benefit? I would say thats mostly used for large companies managing lots of firewalls across multiple regions where having redundant mgmt server is super important, if its smaller company, I would not bother...just my personal opinion.
Andy