Reeder was just limited in all aspects, he wasn’t very good moving laterally, wasn’t quick to the hole and wasn’t good in coverage. Teams, the niners especially, attacked him repeatedly and replacing him with a safety got them knocked around at the los. Wagner has made a career out of being physical at the line and knowing the opponents formations and playbook. Linebacker was the biggest weakness of this defense and everyone knew it. The rams tried to scheme around it, sometimes it worked.
Not only do you not target Wagner, you probably want to scheme away from him. Whether they’re better is gonna depend on if they can find a pass rush. Hopefully Floyd can find a cure for what ails him and someone else(Garrett, Lewis, player X ?) can provide some pressure.
Wagner knows the niners as well as anybody, hopefully the days of them rushing for 180 yds are over. We’ll see if the defense is better but at least the holes will be harder to find.