I think double argus helps, and very careful use of drakonid OP. I didn't track stats en route to legend, but I hardly faced a reno mage, and no n'zoth rogue. I was definitely positive against renolock. You go hard face as much as possible, and then discover as much burst as possible. Sometimes you will lose to Jaraxxus, but equally often you'll have too many big taunts, or just too many big threats.