Jared Allen INSTANTLY comes in as the best DE on the team. I don't know where Remy is going with this one...
BEARS
Houston and Young are both better against the run. Let's say on average teams run 65% on first down, 45% of 2nd down and 20% on 3rd down.
My point was simply, in a DE rotation of Allen, Houston, and Young I would make sure Allen plays most of the time on 3rd down, he and Young would probably split snaps on 2nd down with Allen maybe getting slightly more snaps and then on first down, I would probably have Young get more snaps.
So it's not that he only exclusively plays on 3rd down. It's that the Bears likely will have data on how often teams run or pass depending on down and distance and they should rotate the DEs based on that data. Since teams run more on 1st down, that might mean Young getting more snaps on 1st down than Allen but if it makes Allen feel better to get that first snap of the game on 1st down ie to start then so be it. That would just be one of say the 40% of first down snaps he plays versus the 60% of 1st down snaps Young plays.