Heinicke had a 44.4 QBR last year. Brissett was miles ahead of him at 60.00.
Brissett was 8th overall, Heinicke would have been 25th if included in this list.
https://www.espn.com/nfl/qbr
Overall rating, Heinicke was slightly ahead at 89.6 versus 88.9.
Not to mention, Brissett has a way better arm.
I'd take Brissett over Heinicke every day, and twice on Monday's, Thursday's, and Sunday's.