ToME: the Tales of Maj'Eyal

Hey, I've seen out-of-depth enemies appear, not bosses or anything, and they're throwing me around. I'm level 10-20 dungeons and seeing these unexpected level 35-40 enemies. Is this supposed to happen, and is it conditional on anything or is my Brawler just especially unlucky?

Hey, I got a Brawler to level 16, but I keep seeing these out-of-depth monsters running around. I'm talking monster level 35 standing next to a level 9 wolf, and a monster level 40 surrounded by level 13, 11s. I know what I need to do safe this game is to teleport around them and rush the exit, but ...