They had an entire fall camp, 4 weeks of patsies, and 2 more weeks to get this defense running. They'll continue to improve little by little each week, but I'd say half way into the season what you see is pretty much what you're going to get the remainder of the season. This just isn't a very good squad. Meredith refuses to keep contain, Fish and Compton are slower than heck, Baker and Crick are average at best, the cornerbacks seem to think running stride for stride with a receiver (but two yards behind) is good coverage, and the safeties think it's more fun to take angles and try to catch receivers at the goal line rather than keep them in front at all times. Not much of that is going to change this deep into the season.
And for Pete's sake, can they please use the bye week to do nothing but work on wrapping up, driving, and finishing a tackle. Holy balls.