The 3 mobs I thought about while at work this week.
The melee basically is a high parry rate with a life leech, set to target the closest.
The archer will target the strongest and if your not a player will do 5x damage. The archer is also set up to heal itself.
The mage will target the weakest and is set to have basically all the mage skills. I need to optimize this one a little bit more. Would love to have it cast a finisher nuke if a target gets below say 20% health.