Maybe it's just been my experience, but while Grobbulus was a bit of a pain the other three heroics felt easier than the military quarter (as evident by the fact that I one-shot everything but Grobbulus).I mean, fast mage aggro with freeze spells stops Patchwerk pretty easily (and Harrison Jones provides all the fuel you need to keep pumping out minions and freeze spells), Gluth is pretty much stopped by a mid-tier deck (shockadin/aggrodin), and rogue has a buttload of removal options for Feugen and Stalagg (personally, I went turn 2 Patient Assassin, Preparation into Sap on Feugen, seeing as that'd be the one attacking for 7 if I left it). By the time Feugen came out I was easily able to combo into an Eviscerate, and it's all over from there (particularly if you're able to Sprint on turn 7 to make up for the potential card disadvantage you gave yourself in dealing with the 2 biguns).One fun, and potentially good tip for the fight - if you have room for it in your deck, Dire Wolf Alpha can create some big buffs thanks to polarity. Other cards like Raid Leader and Stormwind Champion work in the same fashion (as does Flametongue Totem if you can keep it alive somehow), but Stormwind Champ is too expensive for the fight, and in the case of Dire Wolf and Raid Leader I'd mostly include them as wincons, so you can start snowballing once you gain board control. I never even saw mine personally.
I found the priest challenge the hardest of the class challenges so far. Usually I can do them the first or second go but this one took me at least four attempts!
I've beaten Herioc Thaddius with a Hunter trap/Murloc deck. I was lucky enough with my turn 2 misdirect to hit each other. Once that was out of the way, the polarity buffed my Murlocs each turn when I had grimscale and Murloc warlord out.
I used hunter for Thaddius heroic, mainly because they have lot of ways to deal with those starting minions between freezing traps, misdirections, hunter's marks, deadly shots, and kill commands.
Actually, misdirection sounds pretty brilliant - it's a 50-50 at a 2-for-1. Also, Timber Wolf would be good for the fight as it synergises well with polarity (though the AI hates Timber Wolf and would make it a high priority kill target).
I beated heroic Grobbulus on first try with a silly priest divine spirit + inner fire deck, steamrolling him with 14/14 taunting lightwell. :p Gluth was the hardest one to me out of this wing, though still none of them was anywhere near as painful as heroic Gothik was last week.
I just wanted to point out that it's incorrect that silencing a deathrattle will prevent Jaws from getting bigger on Gluth. Jaws will still get buffed, even though the deathrattle itself isn't triggered.