Zeraph, maybe you were just not worthy of following in Andraste's footsteps?
Derwood, I agree on the Arcane warrior not being OP. He is amazing at tanking and dealing melee dmg tho. I frequently got more hits and parrys than Zevran and Sten (both of whom I think are Utterly Useless).
The toughest battle with the Arcane Warrior was undoubtedly the High Dragon. Melee simply didn't work. To win I ended up controlling Leiliana for most of the battle and just healing/lyriuming my main char and healing Alistair.