Hi Suraj,
Both switches are actually running as single virtual chassis, hence the VC will only configure one AE to each unit of Firewall.
The diagram is actually borrowed from this link. https://www.juniper.net/techpubs/en_US/release-independent/nce/topics/concept/mf-architecture-network-configuration.html
Considering that interface monitoring weight for each data interface is set to 255, I'd like to know in the scenario which I have described in the first post, does the Firewall will failover as normal when both Active and Standby unit Firewall observed interface failure when SW1 is down?
Regards