Here's Merlin...
We were discussing in our section how IF you were to take the numbers off the QBs and watch them the guy you would think is the rookie is Mannion. Goff is very measured and confident and in most of his snaps smooth with his decision making and of the three the only one who routinely makes the time to look downfield; if a nice pass goes mid to further range it's usually Goff. The occasional INT would plague the others I think IF they were looking downfield and across the middle more often, because this defense is fast and knows what they are doing.
In yesterday's practice there were probably 3x or so where I chuckled and said something along the lines of "welcome to the NFL rookie." Other than that you just wouldn't know he was a rook based on his demeanor. I think he is going to make the doubters look pretty silly, personally. And I think the team knows it too, not just the offense.
My guess is the kid will light Dallas up by the time they play that game. And he'll probably make a mistake or two that will be trotted out there on social media but that's ok. I just don't see any way he's not running this offense soon as the starter, whether it's game 1 or game 3 or so.