More or less.
A ship with 2-dice attacks (or even 2) is no bad thing to have in a squad; because (by comparison) you've got 1-2 more warm bodies to block, threaten range 1 attacks, hunt down agility 0 targets (which they're pretty efficient at) etc, etc.
But there's a difference between 'a useful thing to have in a squad' and 'something you can build a squad exclusively out of'.
It's much like TIE bombers - Long Range Scanners, Homing Missiles, Crack Shot on a Gamma Squadron Veteran is 25 points. It's sometimes called a 'sniper' build, and what it does is put one slow-to-set-up, heavily telegraphed missile shot downrange. Said missile is bloody lethal, and a couple of these ships can that's-all-she-wrote any autothruster-toting ace you care to name in a single shooting phase.
But, once that's done......you're left with 50 points that's providing your squad with basically nothing; a couple of 2-dice popguns and dials and durability that's not as good as equivalent points values of Rookie X-wings.
Which is why you'd never take 4 of them, because even if you took out 2/3 of your opponent's squad in one volley; the remainder would probably beat you.
You can make a swarm work, but the swarm must have an answer for each of the different squad/unit archetypes it might face.
- Agility 0 large ship - Job done. Massed 2-dice attacks, point for point, are the most effective way to kill these things.
- Agility 3+ token-based ship (e.g. focus/evade)- Blocking and crack shot (I guess), but the trick is managing to block and line up the 3-4 shots in arc that you'll need.
- Agility 2-3 with non-depleting bonuses (e.g. concord dawn fenn rau) - crack shot can help, but blocking doesn't. this is probably the swarm's weakest point, because range 1 doesn't help, massed fire doesn't help and blocking doesn't help. This is where stuff like feedback array and black market slicers are priceless.
Alternatively, a 'mini-swarm' with either an ace or a large ship is a nice tool; the latter can engage stuff immune to 2-dice attacks, or prey on action-dependent aces trapped by the swarm.
As with a lot of games; a combined arms force will do better than a single theme.
(which is a shame, as I like flying pure swarms!)