Physical and speed. Basically that is what it comes down to. A player is going to beat his matchup either with speed or strength.
The team has speed. Could use more speed on the defensive side at the LB and safety positions. However, it is a tradeoff. More speed comes with less physical power. Plenty of speed on the offensive side. The team lacks physicality on the defensive side.
The team does not have the mental toughness to play physical though. They pay too soft on defense. They also freelance way too much.
Need mentally tough players who know their role and responsibility and play accordingly. Know your job and do your job and tackle fundamentally.