How dare you.
I assume "All-Decade" means different things to different people.
For me, I think volume matters - the guy who was good for 3 years > the guy who had 1 great season
But I also think the best individual seasons during a decade makes sense, too. But either way, consistency is probably best.
This is weird for the QBs in this setup because you have a situation where the three best QB seasons are all one-year starters thus far. Your most accomplished career is Barrett, a player who has a healthy set of detractors in his own fanbase. Up next would be McSorley, who got notably worse in terms of passing stats each of his final two years.
Then you have compilers like Thorson, Blough and Armstrong. You also have Cook, who led three good teams and was better than his stats, but also dipped a little as a senior.
QBs are weird because they rarely maintain super high levels. If they start notably early, its often because they're at programs without a ton of support. If they're that good, they often go pro.
RB is quirkier because of the grip one school has on it. OSU guys seemed to never be in prominent roles for as long. Arguably the most talented back was behind a bad line and didn't get all the carries. Kevin Coleman only came into his own late.
OL should be interesting. I started dabbling in defense, but realized UW is gonna have a lot of "pretty good, not that top level" guys. But I'm getting ahead of myself.