Trubisky did NOT play with "basically the same players" as Marquise Williams did the year prior. Key players on that 2015 Tar Heels team that went 11 - 1 that weren't on or had limited contributions to that 2016 team:
Quinshad Davis - UNC's all time leader in receptions(at the time) and touchdowns graduated with Marquise.
Mack Hollins - #1 in NCAA in yards per reception(24.8) in 2015. Missed the last 6 games in 2016 with a broken collarbone.
Elijah Hood - UNC's best running back missed multiple games in 2016 and played injured the majority of the season.
Landon Turner - 2015 1st team All American right guard graduated with Marquise. His expected replacement missed the 2016 season due to injury.
Caleb Peterson - Left guard who started 30 straight games missed the final 8 games of the 2016 season because of injury.
UNC also lost offensive coordinator Seth Littrell after the 2015 season. Fedora went with co-offensive coordinators for the 2016 season and it went horribly.
Ryan switzer was the only returning playmaker, and he had his best year by far with Trubisky taking the snaps
I would agree on the OL but the WRs are pretty much the same. All that really happened is that Switzer and Hollins swapped production which even without the injury would have happened because Williams was more inaccurate underneath and favored throwing deep so his game was more suited to throwing to Hollins. By contrast, Trubisky excells in the short to intermediate game and put Switzer in position to use is RAC ability. However, combined, Switzer and Hollins combined for about 1,400 yards both years. It's just that Williams used Hollins more and Trubisky used Switzer more owing to those receivers playing more to those QB's strengths. Both those guys were 4 round picks so really it's a wash between the two.
As for Quinshad Davis, the dude was an undrafted WR that never played a game in the NFL. He is not some uber talented WR. In 2015, Davis, Howard and Proehl combined for about 1,300 yards. In 2016, Howard and Proehl alone combined for 1,400 yards. So again, this was not some massive difference in talent. This was simply the case that guys that are comparable players just became a larger part of the offense with an additional year of experience.
As for RB, Logan was always a better NFL prospect than Hood because Hood is a physical back but slow. He never had the explosion or speed to be a top RB choice. Logan was a 5th round pick because he is one of the fastest RBs in his class and had return ability. He averaged 5.4 yards per carry to Hood's 5.7. The biggest difference in UNC's run game was the fact that Williams himself rushed for 948 yards last year so he made UNC a more balanced offense. Trubisky had that ability but he chose to pass more which made him the better NFL prospect (he is always looking to pass even when scrambling) but didn't necessarily make him the best college QB because running in college is a bigger part of the offense in college.
So it was basically the same players at WR and RB. Guys like Proehl, Switzer and Howard just fit what Trubisky does best so that's why their production increased.
