OKay, what it is it?
So just the obvious turret and Veteran Turret gunner. At two dice in each attack is that a thing I guess
I mean I fly a double-tap Y-Wing with Han Solo in a fairly meme-laden list; since it gets past the normal low int. of most Y-wings, and lets the ship threaten anybody that tries to joust with it; but you are correct, the traditional double-tap build for the Y-Wing and Scurrg is a turret (normally Dorsal, sometimes Ion) and a VTG.
The reason this is popular is you can fit quite a few y-wings (5) or scurrgs (e.g. 3 scurrgs and 1 y-wing) into a list, which results in a *lot* of attacks, and a *lot* of health. It takes a lot of time to burn through all that armor, while your double-attacking team is dishing a lot of damage, and enemies don't have enough tokens to keep their defenses up against that many shots. And because you're making many small attacks instead of a few larger ones, the dice odds tend to even out more over the match (and you'll see more instances of the enemy's defense dice crapping out), so you'll tend to get relatively consistent damage throughout a round.
For Y-Wings that's up to 10 attacks per round. If it's dorsal turrets, each attack is 2 dice (or 3 at range 1). It behaves like a TIE Fighter swarm, but you have to bite through an entire Y-Wing to reduce its power output. Check out Brendon Osmann-Deyman's list which uses 5 y-wings with ion cannon turret, four of which double-tap. That much ionization also gives a lot of control over opponents' ships.
For Scurrgs consider Micheal Maggs' list, which is Drea Renthal and 3 double-tapping scurrgs. The scurrgs have a higher primary attack than do Y-Wings, helping their damage output despite fewer ships, and the one Y-Wing in the list is granting rerolls. It's tough to live through 7 attacks with a reroll and an occasionally spend focus token, some of which are 3-4 dice.
The opponent needs to be squirrely on the approach, since turret upgrades can't shoot range 3. They might be able to initiative-kill one of the lower-init ships if they roll really well, but all that health makes it difficult. They can try to dodge arcs, but fragile aces could struggle with this since there are so many arcs potentially pointed any which way (either by turning ships or turning turret arcs). These lists are winning big tournaments for good reason!
One could do a Y-Wing list in the Scum and Villainy faction as well. Include Kavil and genius w/Proton bombs or Proximity mines and that might be quite a squadron.
What do you think?