Well, it's probably not humanists since I only got one pogrom and only managed to get a soldier, a stormtrooper (Or maybe the stormtrooper mattered since they have fancy personal armor, I don't know) and a tank wreck. But I only use tanks in base defense, so I neglected both that and cyberdiscs beyond researching the corpses.
The factions I encountered the most are church and academy, but I got a whole bunch of trader engineers early on and did a fair bit of research on them. I've interrogated guild reps (but only had one, so no broken), trader engineers (broken, and multiple normal ones), academy espers and medics (and broken ones) and church reverend, zealots and beastmasters (can't remember who I broke for these though). I can't say what else.. Research is an interesting mystery! I wish I remembered what popped advanced personal armour though..
I have only ever seen 2 power armoured dudes. In a trader pogrom early in my game, so I hammered them into submission. They weren't in a state to be enslaved after that
If I meet more, I'll be more careful. I generally try to capture what I can, especially if I haven't interrogated one before (and then take a spare in case it can be broken!). I'll see.. so far armour isn't too much of an issue. My gals tend to survive a hit and a grenade, which is all I require. Air combat was the priority, and I think now it's switched back to guns (time to get lasers or something, although having more LACC and Heavy Cannons and an AutoCannon has been quite an improvement, I want some lazors!).
