Lowkey the defense has improved as it's a lot more organized and stronger with Maguire and AWB back there, despite the stick they've gotten lately after playing 90% of the games this season (Maguire has literally played the most minutes in the world this season, not just Europe
). His fee is the main knock on him but he's not near being the worst defender in the side at all.
The fact that the squad conceded 30 less goals than they did last year, and thats with a declining DDG who's more error-prone than ever, is evidence of that. I think finding a quality partner with pace for him would go a long way, Vic is decent and has had his moments but I don't see him as a long term starter like Blind years back.
Also think a solid LB would help big time too because the drop off anytime Shaw is hurt, which is pretty often unfortunately, has killed a lot of the consistency there at times.
A quality RW would also help AWB focus on what he's good at instead of his weakness moving forward which only gets magnified when you have RW's who like to cut inside a lot more than playing wide.