So for the most part, if you use howl and 2 mechs and howl and 2 humaniods, Yu'la and Xu Fu can be out gunned quickly.
The next 2 however, I found to be more of a complication. But here's how I worked around Chi Chi and Zao using creativity with left over pets and hours of frustrated practice on launch day...
Chi Chi:
Ok I used Unborn Val'kyr, Pandaren Water Elemental, Spawn of G'Nathus for Chi Chi.
Unborn Val'kyr opened with Curse of Doom. I did this right off the start because Chi Chi casts Tranquility right off the bat but it only lasts 2 rounds. Curse out lasts Tranq by 2 rounds. I then just did stupid doesn't matter dmg using Shadow Slash. It will BARELY tick away Chi Chi's health but that's ok. The point of the Valk is not to be the big dmg on Chi Chi. Curse just needs to tick off Chi Chi once, Chi Chi will totally kill your Valk by the time curse ends. Pop off Unholy Ascension to finish. Once UA has been popped, swap out for your Pandaren Water Elemental. Cast Geyser, Cast Whirlpool....then just water jet till dead. Chi Chi will normally be wasting time evading and then casting tranq but wont be able to cast Tranq or heal since your Stun should have gone off an landed Chi Chi in the face after 1-2 Water Jets. If this alone doesn't kill Chi Chi, another Water Jet should. If by chance Chi Chi kills your Water Elemental, Spawn of G'Nathus will enter right at the stun, or the turn AFTER the stun lands. Paralyzing Shock will finish off Chi Chi at this point. If all goes 100% smooth with no major crits on Chi Chi's part, you should be able to 2 pet her and not need your 3rd pet to finish her off.
Zao:
For this little bugger I used Unborn Val'kyr, Water Waveling, Son of Animus
You start off with your Valk once again in this strat. Pop off Curse, Shadow Slash for minimal dmg again until Zao kills you and before you die pop off your Unholy Ascension. Zao SHOULD have wasted his Wish by now healing all the dmg you did to full. If he hasn't, he will in another round or 2. You need him to waste that first wish on your Valk's dmg if you can. Then swap in your Water Waveling once UA is on Zao. Cast Geyser first thing! Then just Frost Shock and Ice Lance till your dead. Zao should be stunned around the same round he kills your Waveling. Swap in Son of Animus. SoA is faster, so once the stun lands and you swap in, hit him with your Interrupting Jolt. Then Batter him down and if you can get off 1 Siphon Anima go ahead and do that since it still deals considerable dmg to Zao.
The key to my strats is getting that debuff off from my Valk, while doing minimal sustained dmg. Then you wanna get in there and stun their faces off! The stuns themselves not only deal close to the maximum dmg you will get on them in one hit, it will also ensure they skip what might have been a vital healing round for them. That third pet is just a finisher for any remaining health. On Chi Chi the third pet could be almost anything really. I used Son of Animus (a mech) on Zao for the dmg increase against beasts to ensure I could beat his Wish healing Timer. And remember with Wish, it will NOT heal him until the round is finished. So if you can get your dmg off to kill him first, he won't be able to heal.
I hope you guys found this useful. My guild tank and I were the first on our server to beat the tournament and receive our Celestial Pets on Patch day. If anyone else has a clever strat please post it The more options people have, the better I think.