Tricky thing to balance, i have never understood the thought process of Solar, how available he wanted these weapons to be and the most important how. Simply decreasing the chance to find Avenger, Gatling etc. etc. (make those encounters significantly harder) in Enclave encounters will most probably force a response from the community how the game is just a ticking timer and it's now longer, because the player will feel like he has to invest more time to obtain these items, everyone is just used that Avenger, Gatling is a common weapon and for a fact i know that it was never intended like that. Maybe it's the time to be stone cold and forget about the whining.
I'd settle for Avenger/Gatling to be found at a difficulty as PPK12 Gauss pistol is or at least a little bit more common than that (face it would add extra flavor to those weapons, we would see more ordinary versions of Avenger, less Gatling and i think that is acceptable and a desirable effect to achieve), if we take a look at Gatling it's already in the special bunker encounter witch is one source and then there's Enclave patrols. My point is you can abuse these encounters close to infinitive ways, as i said tricky to balance if it's the primary source of the item, yet you can't abuse let's say a locker in Glow or that special bunker encounter.
I would like to see less emphasis on Enclave patrols, more on Glow, Ares, special encounters, solves a lot of problems. I'm not saying removing those weapons completely from patrols, but make those weapons appear a lot less frequent, adding secondary arms such as plasma pistols would be a good start also like it is already suggested.
Looks staged to me, like after a squad killed them all then you came in with a looter.... nah that couldn't possibly have been it. BTW no blood? If you want us to take this seriously, repeat your success and post the video on youtube. Failure to do so tells me just as much as if you do....
It's still possible to cripple all their arms with smart usage of combat mechanics with zero percent of failure (not consuming half a day once prepared), once they are all crippled they are harmless, spawn some 4 unarmed mutant mercenaries with mega power fists and watch the show (SS in between if necessary, your reputation is not affected), after that it's loot-fest.
I don't care how he did it actually, i know that it is still quite easily doable.