I have to agree with @Jklinger - while yes, thralls are powerful (even though their damage was nerfed today), knocking people out is a separate talk entirely. It’s just easier than killing people, even for a player; I can keep almost any exile NPC in stunlock with a truncheon so they wouldn’t retaliate, and with a blunted fitting it doesn’t take many swings to knock them out. In fact there are some gimmicks (unless fixed by now?) like Witch Queen boss being formidable to fight, but easy to knock out.
On another hand, thralls get stunlocked too. One of my Relic Hunters (with HP higher than Berserkers get) got obliterated instantly by a horde of cimmerian berserkers that came during purge.
I mean I sort of understand what you’re getting at but even knocking them all out you still have to go around and kill them for loot which is a pain unless you equip a spear. I’m also not sure if you still get xp or not if you KO then kill since I never take that approach. I think its pretty tedious that way and for most people it’s quicker and easier just to let your thrall kill them with a weapon and probably why no one really sees it as being much of an issue.