In my opinion the defense really doesn't need any tweaks, it already works quite well. However, in my opinion the department where we suck the most and I speak as a fan is the attack.
I'm not satisfied with our current attack, so in my opinion that's where we should improve.
Why did you mention the defense? in theory we are the team that has conceded the fewest goals
Not really? I mean yeah defense doesn't need tweaking that's true, because they have 8 goals scored on them so far, which makes it look like they are great, and only 22 goals scored, that could have been a bit more, but it is not terrible neither. What stats are not showing is that the return of having very low goals scored on them is the fact that they are playing quite defensively, which means that they are not going to concede many goals of course, but that's not a problem on offense to keep scoring when the idea is to keep the defenders at defense.
Look at City, they failed to win games for 7 games in a row, and yet when they were attacking, their defense still played all the way towards the attacking line, you could see Gvardiol, a centre back, shooting at times. Juventus doesn't have that help from defense when attacking, they leave the attackers all by themselves to score, which is why I do not expect attackers to do better, that part is wrong if you ask me, they need more help from defense and midfield.
https://www.sisal.it/scommesse-matchpoint/blog/analisi/miglior-difesa-della-serie-a-di-chi-e-al-momento-i-dati-aggiornati if you look carefully on this site they also say it, at the moment the best defense in Serie A belongs to Juventus
the problem isn't in defence, obviously in my opinion, it's in attack or midfield.
why do i said attack? usually the midfield also filters some plays and works as an aid to the defense, so it's ok
however, a serious attack is missing