I know Pete thinks "pass first" is a dirty word, but it does seem like the team's run game priorities have shifted this year while Lynch has been out. Previously, the pass game complimented the run game. The Seahawks led the NFL in both 1st down rush rate and play action rate. The pass offense took deep shots to try and keep the safety out of the box.
But in 2015, the run game is complimenting the pass game. Seattle is passing more on 1st down, running way less play action, and taking fewer deep shots. Seattle still runs the ball a lot relative to other NFL teams, but the run game is more about keeping defenses honest to soften them up for the pass attack, rather than being the beating heart of the team.
For the former role, you must have an elite RB to have success. For the latter role, you just need a competent RB.
Both Michael and Brown looked capable of competence.
Michael's situation feels eerily similar to Knowshon Moreno early in 2013. A former high pick RB considered to be a huge disappointment, gets one last crack at a starting job due to a ton of injuries. And he ran with it. Moreno only really had that one nice season, but in 2013, he helped compliment Manning's elite passing offense. But when he faced an elite defense in the SB, he folded like a lawn chair. I think Michael can be very good against most defenses but against elite run defenses I don't think he has the special qualities to overcome the way Lynch has.
I do believe in our running game, as long as Wilson can continue his hot streak and make his arm the centerpiece of the offense, and as long as we don't put our hopes on Michael beating an elite run D all on his own.