Wait to see who is starting for ARI. If it's Skelton or Kolb, start Fitz. Otherwise, start Tate.
Lindley is not ready for NFL duty yet. He's not capable of progressing through his reads fast enough, he doesn't make hot reads on blitzes, his pre-snap recognition is poor, and his accuracy right now is abysmal.
Skelton won't win many games, but at least he's not incompetent and can get Fitz the ball.