Certainly Josh's PCL had a big impact on the season. The lack of creativity on play calls is what stood out to me. Watching KC, they had a new wrinkle play almost every week. The Bills offense was brute force effective because teams elected to give up Josh's rushing yards rather than Stef's receiving yards. They need to be able to scheme Stef open. And Josh/Stef needs to occasionally beat double coverage when they don't.
Now having said all of that, going into last season, I really convinced myself that Kromer was going to be the difference maker. The fact that the o-line was breached more times than the southern border, was really the root cause for a lot of the "ills" in the offense. A second or two more of pocket time would likely have allowed Josh to wait for Stef to beat double coverage.