Old Gods had Cultist, Ravaging Ghoul, First Mate, Blood to Ichor, Bloodhoof Brave, Malkorok, and Shieldbearer. Probably the best ratio of "good" cards and the class still struggled during the meta sometimes. The Un'goro set was pretty underwhelming outside of Hatchling but what can you do. Could say the same of many other classes, because Un'goro was defined more by the neutrals than anything else in my eyes.
Warrior did not struggle in Old Gods. Heck, Old Gods was warrior stone. That was when Pirate Warrior became a real deck (Chakki and others even brought it to a bunch of tournaments during that cycle). Tempo Warrior was the best deck in the meta until Dragon Warrior took its spot like 5 or 6 weeks later. Control Warrior was really good, and was seeing play with several variants, including fatigue focused lists. C'thun Warrior was better, both the control and cycle versions. Warrior had the best combo deck with the Raging Worgen/Charge OTK. People were even playing spell Warrior with Yogg. I don't think there's ever been a meta before or since where one class was so good at so many different things. Aggro, Midrange, Control and Combo were all the domain of Warrior and Warrior was by far the most played class in that meta.
Warrior was so good it earned the class an unwarranted and unfair nerf to Execute and is probably the reason Jade Idol was printed, to make sure decks where the win condition is remove everything and kill with fatigue damage would never be viable again.
But Jade druid isn't a midrange deck either.
Uh.... yeah it is? It's not a tempo deck, or a control deck, or an aggro deck. You could argue it's a combo deck, but if it is, it's a midrange combo deck--and you could say the same thing about taunt warrior.