Hearthpwn

Revenge
You don't really see this card being played a lot, but I think it's a shining star in this meta. When you're still at high HP, you can use it in combination with Death's Bite, Whirlwind or your own Armorsmith. But if you're at low HP, it perfectly counters a full zoo or patron board, dealing 3 damage to every minion on the board. Make sure you know what deck you're facing when deciding whether to use the card early or late game.

Coldlight Oracle
Changing it with Acolyte of Pain is perfectly fine. I've won a lot of games with acolyte, haven't really tested with oracle yet. The reason I choose Oracle is because it provides a better body against aggro compared to Acolyte (2 attack), it's a guaranteed 2 card draw, where Acolyte sometimes gives 1 or 0 cards, and it also draws cards for your opponents. Against control priest you can sometimes mill their hand, and against any other kind of control deck you can expect the game to go late game. This way you can fatique them, as they have their own carddraw as well, while you have infinite armor.

Abomination
A good aggro counter. Sometimes they don't know how to play around it. 

Only 1 Big Game Hunter
In this meta you only really need 1. You have 2 shield blocks as well. And with this deck it's fairly easy to get 10+ armor. So 1 BGH is enough.

Earthen Ring Farseer
This was my substitute for 1 BGH. Had no better idea. It's a body + heal against aggro. Feel free to suggest better things in the commands. 

Iron Juggernaut
The original Mayweather deck I posted above used Ysera. I substituted it with Iron Juggernaut because I don't have Ysera. It's stats are good, and it can draw out a Shadow Word: Death to safely play Grommash later. Because of this deck's huge lack of burst damage (pretty much only Grommash + Cruel task masker), I really like the bomb. 

Ironbeak Owl
Use it wisely :) Thinking about replacing it with Spellbreaker. During mid to late game I usually have a lot of unspent mana, and spellbreaker provides another body. 

Zoolock
Should be an extremely easy win. Try to mulligan for your weapons and Armor Smith. Later in the game you will get so much armor from Shield Block and Shieldmaidens that your opponent will eventually concede :)

Hunter
Same with Zoolock. If you are able to deal with the early game, your opponent will run out of steam later on. Don't be afraid to use 2 damage shield slams.

Control Paladin
In my opinion the hardest match-up. If you can, save the only owl in your deck for Tirion. Your armor smith should deal with his muster for battle at the start. Trade wisely, and it will come down to the late game. 

Control Priest
You'll get a lot of armor during this match. If it's recombulator steal priest, be considerate about placing Belchers down. They'll just steal it from you. Using the mine from Iron Juggernaut and using Grommash at the exact right time, you should be able to win. 

Grim Patron Warrior
Be careful not to play <3 attack minions after turn 7. Revenge is a total board clear if you're at low HP. You can also use shield slams and normal slam. If you make them effectively run out of steam, you will win in the late game. 

Machine gun mage / Mech mage
Machine gun mage: Use weapons to clear Flamewake / Mana wyrm. Mech mage: Use brawl and your taunts at the right times.