Schwartz did an excellent job of taking the Lions out of the cellar of the NFL. They went 0-16 the season before he was hired as head coach, and he got them to the playoffs in only three seasons. His biggest problem was his inability to sustain that kind of success. Things got too comfortable after that playoff appearance, and the team responded by collapsing in the second half of the season in both 2012 and 2013.
They utilized the Wide 9 quite a bit, much to the chagrin of many fans. They rarely blitzed and relied mostly on their defensive line to generate pressure. Stopping the run was an issue up until this past season, and pass rushing was always pretty inconsistent.
The Lions just always seemed to have holes on the roster. Defensive tackle was a strength, but defensive end was never able to reach an elite level. The linebacker play was excellent this past season, but the secondary was pretty mediocre against the pass, like usual. In short, the Lions just really never had a consistent amount of talent around Suh, and they seemingly weren't able to scheme around that most of the time.
It's tough to say since Gunther Cunningham was the defensive coordinator here. Schwartz obviously played a large role in the defense, but it's unclear who had more influence on it. Plus, Schwartz never really had a defense in Detroit that, as an entire unit, was as good as some of his best ones in Tennessee.
Strengths: They were able to put a lot of pressure on opposing quarterbacks in ways that didn't always show up on the stat sheet. Also, the Lions were dominant against the run for most of this past season, and DeAndre Levy had a career year at linebacker.
Weaknesses: The secondary was always the weak spot, and the Lions were prone to giving up a lot of big plays as a result. Also, they were unable to consistently generate turnovers, which really hurt them the last two seasons.
6) Do you think Schwartz would be a good defensive coordinator for the Bills? Why?
From a personality standpoint, I think being a defensive coordinator would be a much better fit for Schwartz than being a head coach. From a coaching standpoint, I'm just not sure what he actually brings to the table based on his time in Detroit. Clearly he had success in Tennessee, but the Lions rarely relied on their defense to win games with him as the head coach, and if he's insistent on running the Wide 9 more often than not, I wouldn't want him to be my team's defensive coordinator.