Long-time Pats fan here ... Here's the differences I see in Brady after moving south:
1. No first-down screens. Staple at NE, always gained 3-7 yards. As a result, 2d and 3d downs were manageable, and either run or pass was an option, keeping defenses off balance.
2. Limited intermediate between-the-hashes throws. Another NE staple -- where Gronk and Brady's favorite targets, Julian Edelman/Wes Welker, made their living. That's where Brady thrives, and why he asked for AB. Yet Arians not using AB or Godwin that way.
3. NE took deep shots only when leading by more than one score. In other words, no critical downs wasted on low-probability plays.
IF ARIANS MADE #1 AND #2 THE CORE OF THE OFFENSE, BRADY WOULD HAVE MORE CONSISTENT SUCCESS.