The "our defence is fixed" or "we have improved in defence" bullsh*t which is based on the comparison of "goals against" or whatever stat with the last year (which was an anomaly because Jose constantly undermined his defenders and played the likes of Herrera & McTominay in defence to prove a point) needs to stop. Until last year, we conceded the least goals in the league starting with LVG's first season.
If you want to compare our defensive record this year, you should do it not just with last year but also the previous ones where the defenders were more or less the same personnel (Smalling, Jones, Rojo, Bailly etc.). We had the best (or joint best with Spurs) or second/third best defensive record in the league starting from 2014-15 season with Van Gaal until last year. And some are talking about our defence which conceded 25 goals after 21 games and is the 6th best in the league as of now as an improvement. It's not.
2014-15 (Van Gaal's first season): 37 goals conceded (fourth best in the league after champions Chelsea with 32, 7th placed Southampton with 33 and 3rd placed Arsenal with 36)
2015-16 (Van Gaal's second season): 35 goals conceded (joint best record in the league with 3rd placed Spurs; champions Leicester & 2nd placed Arsenal conceded 36 goals)
2016-17 (Mourinho's first season): 29 goals conceded (2nd best record in the league after second placed Tottenham with 26; champions Chelsea conceded 33, 3rd placed City 39, 4th placed Liverpool 42)
2017-2018 (Mourinho's second season) : 28 goals conceded (2nd best in the league after record breaking champions City with 27 and 3rd placed Spurs with 36, 4th placed Liverpool & 5th placed Chelsea with 38)
Now that's what I call improvement in the defence. The number of goals conceded getting lower each year. Not to mention the fact that measuring how solid a defence is not just about the "goals against" stat. We concede less than we'd normally do this year because we play defensive, counter attacking football. When we intend to attack this year, there is goals conceded too softly for a good defence it's simple as that. We spent a small fortune on our defence and didn't fix anything. I don't trust either of our CBs now.