The offense started to evolve the minute Dorsey was fired and Brady took over the OC role. The game plans were more complete and far less reliant on Allen and Diggs being heroes, resulting in a much more balanced offense and significantly better production by the team as a whole (not to mention taking pressure off of the defense by effectively running the ball). Diggs didn't like his reduced production, but the only stats that matter at the end of the day are wins and losses.
Dorsey as OC - 10 games:
Winning %: .500 (5-5)
Points per game: 28.6 (skewed by weeks 2-4 blowouts against MIA, LV, WAS. 23.3ppg in the other 7)
Diggs receptions/game: 7.3
Diggs yards/game: 86.8
Diggs TD/Game: 0.5
Brady as OC - 9 games (including playoffs):
Winning %: 0.778 (7-2)
Points per game: 27.4
Diggs receptions/game: 4.9
Diggs yards/game: 43.1
Diggs TD/Game: 0.1