So...just my opinion...
...but Jimmy is a big reason why they keep beating the Rams. It not because he is an all world QB. Its because what he's good at plays directly into the weakness of the Rams defense.
They are soft over the middle. I'm not talking about the Line. Donald is anything but soft.
They are soft at ILB and safety. That where the 49ers strike and Jimmy never holds the ball long so the rush can almost never get there. What Jimmy does well are quick hitting, over the middle short to intermediate passing to guys who are YAC monsters like Deebo, Aiyuk, Kittle, and more and more now Jennings.
Also, for as fast as they are on the line, they are undersized. The run game hurts them, the misdirection confuses the LBs and Safeties, and play action passes over the middle kills them. Its a "styles make fights" situation.
Ask yourselves, where are the Seahawks strong on defense? Its no wonder that Jimmy and the 49ers have trouble with them. Wagner has been a thorn in their side for a decade and ALWAYS seems to have his hands on the ball at some point during the game.
The Cowboys?
I dunno. I think the 49ers can win but I'm certainly not banking on it. It might be another "strong where you are weak" situation with them. They get turnovers but also give up big plays and the 49ers are one of the best teams in the NFL at creating explosive plays.
Then again, thinking of the Dallas receivers against 49er secondary is scary. Still....the 49ers have been able to mask that pretty well and despite their problems at the position managed to finish 6th in the NFL in pass D.
Basically I can see both teams with advantages and no idea how to weight them.
Should be a fun game.