Mike Shanahan’s offense was plenty favorable to QBs. If there were social media back then people would be talking all about how Shanahan made Brian Griese viable and Jake Plummer into a Pro Bowl QB. He was just terrible at scouting QBs… a trait that his son actually kinda share if you think about it.
Using EPM after 20% of the season feels like a weird choice given how much sample size matters for these kind of stats even compared to raw stats. As well as how they’re so situation-dependent, as in Cade in Barnes situation would obviously not be putting up half the shots that he’s putting up in Detroit given the other talents on the team.