Responding about *just* my cleric
(little ms. rule-breaker)
Before whatever lvl archers get that awesome run-kite-poison-aoe (lvl51?) I would party with a mage...however after that magic-archer-level....well I've had two really good duo parties with 5x archers and ...just...wow. I got way more kills and exp in both Abyss and CP.
Tho I used more HP stones/pots because I had to heal myself more often coz i couldnt just stand still by the archer while he AOEd (because they were kiting)