It is, in my opinion, generous to Newton to say the two QBs are performing at similar levels. But the answer to your question is obviously field position. And I don't mean the average field position that is affected by Seattle's superior return game. I mean the type of field position that translates into easy scores: that is, turnovers. Going into yesterday, the Panthers had forced 28 turnovers to the Seahawks' 11. Interception return yards were more than double for Carolina, and remain at around double.
That's certainly part of it - the Panthers are getting the most production from defensive turnovers of any team in the league. Some of the statistical basis of this discussion has shifted since we started talking about it due to Wilson's big game Sunday, but we can use EPA to isolate how much the passing offense contributes to team scoring. The Seahawks have now nosed ahead of Carolina in
passing offense EPA, 69.11 (11th in the NFL) vs 63.20 (12th). I don't have historical stats, but this time last week Newton certainly would have been ahead in this stat, despite trailing him in many of the traditional passing stats you mention.
That's really my point in this discussion of statistics: the Seahawks passing attack is not putting as many points on the board as the stats you quote would suggest, and Carolina's is scoring more. This is true to the extent we are able to isolate the contributions of passing attack. I would not dismiss this as a fluke or irrelevant without further study and understanding why. Some of those who've looked deeply into the film have found flaws in Wilson's game and strengths in Newton's that may partly explain what we're seeing.
And all football stats are team stats, of course, and trying to boil them down to the individual's contributions is an imperfect science. None of the stats we quote account for strength of receiving weapons, strength of offensive line, strength of schedule, environmental impact, etc. Hell, we are not even getting into the impact of the quarterback running even though that is a big part of both Newton's and Wilson's game.
When one team (and one QB) is significantly better than the other at yards per game and per play, rushing and passing, and that qb turns the ball over less frequently, it's pretty lazy to just point at the scoreboard. Carolina's defense is its MVP by a good margin. Not Cam Newton.
I'm certainly not trying to suggest we should just look at points scored and force rank on that basis. That would be pretty lazy.
I started this discussion by pointing out that the film people tend to like Newton and the stats people like Wilson. You seemed pretty dismissive of the film-based approach, so I have been trying to demonstrate that the statistics you're quoting aren't capturing the whole story. At the end of the day, games are won and lost on points. Statistics draw a lot of their validity by how well they correlate to and predict points scored. That's why on-base percentage has more merit than batting average - by including walks, we explain more of runs scored. Most football statistics are nearer to BA than OBA in terms of their relevance to scoring. When we see a case where the relationship between statistics and scoring is weaker than we expect, it behooves us to ask what the stats might be missing.
And again, the other massive difference between baseball and football statistics is that it is much harder and perhaps impossible to isolate the contributions of individuals to team events.