I think that's the first time anyone has ever accused the Firefly of being fragile or undergunned.
There are very good reasons why nobody else has said that.
In the succession wars, especially with canon designs, it's a bruiser among lights. But...
When I think of Firefly, the one that comes to mind is the -4DA in Wolf and Blake. It's lancemates are a Talon, Wolfhound and Locust. Compared to the other three, which are
good variants, it is undersinked (and thus underarmed,) short-ranged and entirely too bloody slow. Armor is about as good as it can be for weight. Unfortunately, it can reasonably expect to run into mediums as fast or faster than it is.
I consider the thing a deathtrap for the guy who boosts the initiative of the recon lance.