On end game playing, get a T4 thralls (armorers mostly) is really boring, because you have to kill in a spot several times and wait to the thrall to be here in the next spawn.
A solution to this, maybe adding more T4 thralls to the dungeons being a reward to the effort of finish the dungeon.
Yeah, it would actually be kind of cool to complete a rescue mission in a dungeon and at the end have a T4 artisan join your clan. Be a nice change to have a willing thrall instead of them always having to be enemies that you subjugated.