Wiz is overall quite sensitive to errors and thus doesn't look like the best class for trial of iron solo, but is pretty competitive I'd say. I'm still not convinced it's doable legitimately at all. For regular solo though where you aren't punished for a single small error, he's one of the best classes. Also casters have probably the best power scaling so he's quite OP by the endgame. I don't have a wizard main, but I just tried to duo Thaos letting him kill my main and do it with the wizard. Must say he can take the fight pretty much head on.
well on my trial of iron im up to heritage hill, and ive cleared cliaban rilag. Im relatively confident going forwards as nothing ive encountered so far has been able to eat through my summon shield before i can replace it, my only problem is a lack of dps, but when i get the fire aura that should get much better because as it is ive put all my talents into being as tanky as possible, large shield, heaviest armor, shield and sword, cautious attack.
as a result mostly i rely on wearing the enemy down,however I can use level three scrolls so if the need arises i can nuke people.