Did any one try mage armor on him to buff his AC?!
All they say he dies the most but not how and by what and you also assume that you deal with semi intelligent humans playing the game not idiots who will let there characters stand in aoe fier or acid areas until they are dead.
Did you ever play a MMORPG? When you start dealing with other "humans" and there "situational awareness" you start being surprised. I start ether feeling like a God because you made the connection Fier= hot = me + standing fier = bad = move out
While other cant make that simple connection or you simply loose all faith in humanity at all.
Unfortunately I didnt have the chance to play too many MMORPG, RPG a lot, but not MMORPG. All of the knowledge I have regarding MMORPG can ve summarized in "please do not call idiots to other players".
Besides, its irelevant, in RPG, you generally try to take the wizard first, so Mage armor on or not, i would always try to hit him. A moderate AC is irrelevant if you have advantage in a ranged attack, and its useless against AoE/surfaces.