So hangar bay is a newish event format and I think it's great to see some thought put into formats that are not quite 100 point dog fights. I have wanted to see this particular list building format for some time.
Arsenal lists include one list of pilots that you share with your opponent. And two potential lists of upgrade cards that you pick from after seeing your opponent's pilot list.
This allows players to bring to the right equipment against the right targets. It increases the utility of upgrades that counter popular builds and allows players to counter lists that they would otherwise be weak to.
This allows for some flexibility in what you bring to the table each game but does not require taking two full lists of ship models to an event.