If you don't think the ability throw TD's in this era is troubling - you're the one with the agenda. It pretty much means you need to have an outstanding running game and a lights out defense in order to be successful. If you're a leadoff hitter in baseball, you're main job is to get on base. When you begin to lack that ability, you no longer are valued as a leadoff hitter.
Another thing, Canada's offense was not good. Virtually everyone agrees with that. However, if you need everything schemed up perfectly, you probably can't play QB in this league. And, this is why Tomlin had it on the table to bench Kenny after the Cleveland loss not fire Canada. I'm willing to bet if you asked Canada, if he felt handcuffed a bit because of the QB - he'd probably agree. Again - neither helped the situation. The only thing I know, it looked like when Mason took the helm - the entire team was relieved including the HC in a reluctant manner.
When you've got Jackson, Burrow, and Watson in your division, you better have a guy who can put the ball in the endzone. Otherwise, your entire team (defense, offense, s/t) is going to be beyond stressed.