MA with guardian trait makes a sweet tank. OFC pure dps gotta wait a bit longger before attacking but you gonn have all that extra dps once timed skills are used. My wife(cleric and I ,MA, can duo any 3 man our lvl or below, and 5 men up to arid. So no, melee dps are NOT useless in caves. Also, remember that melee DoT causes 0 instant dmg, so does not generate aggro, which makes ma and theif a valuable asset in dgns.