It was my 9th mission, and I tried it with a zenith cruiser (I did the first 8 before the difficulty scaling change, not sure if that matters). Never actually beat it, but loaded out with bomber bays and laser modules I felt like the gattlings were pretty manageable (not so much before I switched to that loadout, though).
The third goal of the text was a little bit confusing, I felt like there was something I should have been doing instead of killing the gattlings (like disabling them somehow?), but if there's a secret to the mission, I couldn't figure out what it is.
It feels a little cheeky to go in, figure out what the mission is, and then reload with a special loadout based on that, though (and since I've done quite a few missions, I generally am going deep into AI territory to get to those wormholes, meaning I'm basically stuck with whatever layout I go in with - if I try to refit I'd surely lose the mission).