Have just gone through four kobold archers, none of whom got past first level.
The most recent of them, Pi'tamki, was given - as a first level quest on the first dungeon - "infestation of cave orcs". Cave orcs are seventh level. Pi'tamki was first level. Pi'tamki did not last long.
EDIT: Pi'tamki's successor, Pi'jukki, was killed by a crow having not gained any XP whatsoever. The quest for a semi-successful kobold continues...
EDIT [18:51]: Pi'viski is kobold #6. So far, successfully killed a fruit bat and an insect swarm.
EDIT [18:53]: Pi'viski successfully shot several giant mice, but then rapidly died upon reading a scroll of Summon Monsters.