I seriously don't get all the hate some people here have for Arians. He's a human. He's an exceptionally good football coach. He's won a Super Bowl. Arians was smart enough and humble enough to get out of Brady's way and let Brady manage the offense. Arians Cardinals teams were (usually) a worthy adversary when he was their coach. By all accounts I've heard, most of his players loved him as a coach. He didn't get sucked into Antonio Brown's antics.
Arians was lucky??!! Abso-freakin-lutely "lucky"!
Luck = Preparation + Opportunity.
I wish Bruce Arians well in whatever's next for him.