You see, this ignores the whole "time" element. Going by your logic, if TB threw an INT on his first pass as a RC, amd only that pass during a game, then he'd throw an INT 100% of the time. And, therefore he sucks.
We can do better.
The answer is to work on the guy for one more year and see if the coaching staff can develop him.
I'd still rather him than TT, at this point. But, if I were a coach, I wouldnt.