This season i've played only this deck and i've reached legend fast, this deck is the strongest on ladder to climb i think, it's not a joke, in past i've tried secret paladin, midrange hunter, all the strongest archetypes and this in my opinion is the best.
Why those cards?
Justicar Trueheart without auchenai is still good? yes. Why? Hunters. There are a lot of Hunters in Wild, this beats their oppressive hero power.
Why no those cards?
Auchenai/circle/flash heals: because if you have other options to board clear is better doing that in one card instead in a combination of cards.
Cabal Shadow Priest with 6 six drops you can't put more of them.
Proof of legend
Hope you try this one, and let a comment and an upvote! cheers!