Pretty sure it was because of me being level 12, heh. Went there for the tin though.. so we got what we came for!
Anyways, yeah. Those witchlords are at least level 8 Sorcerers, maybe level 10. Was a helluva fight, got the blood flowing and was fun.
XP seemed just a tad shoddy on the Witchlords specifically, but like Nef said, probably a number issue with my level.