I get you, but I don't think it's quite as simple as that. We hardly conceded any goals in our 55 season, which wasn't down to how good our defence was per se, it was down to how we played, constantly stretching teams, possession based defence, tiring out our opposition to the point when we did give the ball away, they were less of a problem.
I hope with a full pre season, and more of *his* players, MB will work in a similar fashion.
The vermin don't have a great defence, they did something similar last season.
Where your good defence is under more scrutiny is in Europe, obvs.