No. Whilst having mercenaries is required in the Frozen Horror if you expect to have any form of success, I feel Mage of the Mirror should be more privatized. It's not as difficult as Frozen Horror and thematically speaking, Millandreal is kidnapped so leading an army through Glenis Fen will sound alarms and endanger the girl even further. Penetration would require a small group to rescue Millandreal.
The quests would still be insanely long, but they're more manageable. And I'm not requiring the Elf to wield the Ancient Staff all the way through, he can always pull it out when facing a spellcaster, it would help protect all other heroes from affliction and damage causing spells.