I had to look up automatic critical hits because I was unfamiliar with the rule.
It's not something that leaps to mind for most people.
Like I said, it's often overlooked/forgotten until someone like me comes along with citations and reminders.
That's a lot of firepower to get an autocrit on a 0-99 ton vessel, which rolls on a table half filled with results it can safely ignore (Jump Drive, Boat Deck/Hangar, Screens, and Frozen Watch are likely free hits for small craft crits), though I will grant that the rest are probably catasrophic.
To look at it from a different angle ... you basically need 1000 tons of big craft to obtain either 10 turrets (double or triple) or 1 bay (probably 100 tons, although there are some edge cases for 50 ton bays) as a single battery.
In other words, you want 1000 tons of big craft to get a code: 8-9
single battery to shoot at small craft.
If you want more weaponry than a single battery, you need a bigger big craft.
In LBB S9 on p14-15, the two DE classes are roughly MCr730-735 for a 1000 ton starship with a variety of weapon batteries.
Imagine refitting them such that they were armed with a single battery ... ONE ... made of 10x triple beam laser turrets ... or a single 50 ton missile bay for approximately the same overall construction price.
Now consider that a Heavy Fighter (LBB S9, p26) costs MCr105.33 for a 50 ton small craft with a mixed triple turret of 1 sandcaster, 1 beam laser, 1 missle rack.
A single "One Battery Wonder" destroyer costing MCr730-745 would need to defeat/destroy 7x Heavy Fighters in order for the ledger to "balance" on construction costs between the two choices, in terms of equivalency of exchange. If the "equal costs" setup had a single destroyer (with a single BIG battery) on one side ... and a swarm of 7x heavy fighters on the other that can fire 2 offensive weapons EACH ... I would probably be tempted to bet on the fighters rather than the destroyer. That kind of attrition battle is unlikely to favor the "solo" Big Battery on the 1000 ton starship.
Hence why I'm of the opinion that the "best fighter destroyer" design would weigh in at 1900-1999 tons (so still Hull: A code) which gets a -1 DM to be hit due to size. The 1900-1999 ton hull gives you 19 "turrets worth" of tonnage to spend on armaments, which is enough for a bay weapon and supporting secondary weapon batteries to round things out. Could make things very interesting in LBB5.80 combat terms.