I don't think it's so much that Courage is useless; it's that being surrounded is so tactically undesirable that you should really avoid it at all costs. Except in Big Room, cavernous levels, Earth temple, etc. it's pretty uncommon to have more than one or two monsters attacking you at once if you're fairly careful. This is one of the rare situations where being surrounded is very difficult to avoid and you don't have much room to retreat.
Hoping to win with every class, doomed. Archer, Barbarian, Bard, Beastfighter, Druid, Elementalist, Farmer, Fighter, Monk, and ULE Priest down.