Tough to say but I want to give the edge to the 2019 team. I think the advantage comes from the defense
Quarterback: Fairly even, both Morgan and Khaliq were capable in a game manager sense. Maybe a little advantage to 2019 because of the way Morgan played that year.
Running back: Have to go with 2003. Barber and Maroney were on another level. Plus the running game had help from Thomas Tapeh. Smith, Brooks and Mo were certainly good, but I think they weren't on the same level as Barber and Maroney.
Tight End: 2003 again. Matt Spaeth and Ben Utecht made that a strong position.
Wide Receiver: 2019 by a mile. Bateman and Johnson were phenomenal, plus they had Autman-Bell to get some of the passes, too.
Defense: 2019. Chris Williamson, Antoine Winfield Jr., Benjamin St. Juste, Kamal Martin and Carter Coughlin all made that team a force.
In terms of schedule, 2019 opponents finished the season with a combined record of 82-82. The 2003 opponents, meanwhile finished 75-88. It can be noted, though, that one of 2019's opponents was FCS while all of 2003 was against FBS.
Against ranked opponents, 2019 team went 2-2, with wins Vs. No. 4 Penn State and No. 12 Auburn, and losses Vs. No. 20 Iowa and No. 12 Wisconsin. Penn State finished No. 9, Iowa finished No. 15. Wisconsin finished No. 13/11. Auburn finished No. 14.
Against ranked opponents, 2003 team went 0-3, with losses to No. 20 Michigan, No. 15 Michigan State and No. 20 Iowa. Iowa finished No. 8, Michigan finished Nov. 6/7 and Michigan State finished unranked.