Enemy wizards needing 'epic gnolls' in order to protect themselves, is a bit ridiculous.
At epic levels, any enemy wizard should be able to rape an unprepared party, like in TOB. But in MOTB everything comes down on spamming level 9 spells or the occasional Vampiric Feast... it's not even strictly necessary to cast protections or buffs on the party, which is pretty lame.