So, here's something interesting. I've been attacking at the Slags Gate a lot (with my perception buffed as high as I can), and was always getting 1 ripped part, and 2 other heavy parts. All these battles were won in one round, with two techniques used (Rain of Bullets and one other tech). Then, I switched to a different setup where I was winning fights in 2 rounds, with 4 techniques used, and I started getting 2 or 3 ripped parts, and sometimes only getting 2 suit parts at all. So it looks like the killing the guards quickly is the way to getting better suits. I don't know if it's based off of rounds or techs used or what though.
EDIT: a few samples:
(1 round = 2 good, 1 ripped) [30 samples, confirmed]
(2 rounds = 3 ripped x1, {2 ripped, 1 good} x4, 2 ripped x1, {1 ripped, 1 good} x2, 2 good x1) [9 samples]
(11 rounds = 3 ripped) [1 sample]
(23 rounds = 1 good) [1 sample]
(34 rounds = 1 ripped) [1 sample]
I could imagine it working something like:
- For each round in the fight: pick one of {hat, pants, shirt} at random. If that part is good, downgrade it to ripped. If that part is ripped, destroy it. These are probably still subject to another roll to see if they drop, increases with perception bonus. Could be more complicated and only count rounds where I actually did damage, or perhaps as a chance proportional to damage done.
Ah, come to think of it, that explains why for a while I was getting EITHER {2 ripped, 1 good} OR {2 good} from the slags lab guards. If it picks two different slots, you end up with 2 ripped+1 good, but if it happens to pick the same slot twice in a row, you get 2 good because the other part got destroyed. Got the 2 good ones about a third of the time, so that is consistent with that theory at least.