Seems like every other team expected to sign Bridgewater (Speculation)

https://lasportshub.com/2020/02/05/los-angeles-chargers-better-tom-brady/amp/2/
“ If we average his five starts into 16 starts then Bridgewater would have finished with 3,856 yards, 29 touchdowns and six interceptions. The only quarterback to finish with 3,800+ passing yards, 29+ passing touchdowns and six or fewer interceptions this season was Russell Wilson.

It only happened in five instances in the entire decade, belonging to Wilson, Aaron Rodgers (twice), Tom Brady and Drew Brees.”

Your analysis relies on the assumption that Tampa was a typical performance.

Accounting for that exception (career best game) you get a 17TD season which is also around his career average.

2014 12 Starts 14 TDs 12 Int 3 Fumbles
2015 16 Starts 14 TDs 9 Int 8 Fumbles