It seems pretty obvious to me that Townsend was recruited by Payton to perform a very important but actually quite small (for a halfback) role in the team and to the strengths of the players around him. He plays very well within the limits that Payton has set for him, looking at his stats simply confirms what is easily observed. For example, forced drop outs are obviously something Payton demanded from him and he has somewhat delivered with 14 in 22 games. Compared to say only 2 tries against 19 try assists and 12 line break assists, obviously the objective is to help others score tries and make breaks not to score them himself. His average running at 50 metres per game is hardly top level, but that's not his job. Similarly, his tackling effectiveness at 87% is not stellar. He does the things that the team needs him to do very well and there is no demand on him to do the things that he doesn't do very well. Payton has him playing to a very simple game plan, where have we heard that before.
If we ask pretty much anyone they would say that Townsend is doing a great job for the Cowboys, which he is, but his role is limited by what he can do, the fact is he is not an all round quality halfback. What is obvious is that Payton has him and the team playing to a plan that suites his talents and skills whilst at the same time doesn't require him to do things that he simply can not do.
Always a Bulldog