Everton and Aston Villa have both had average defensive performances this season, with both teams conceding goals at a rate that is not exceptional.
At the other end of the table, Chelsea and Manchester City have been among the best in terms of defense this season. However, it's important to note that these two teams have also conceded some goals themselves, which means they are not immune to their opponents' attacks.
The issue for Everton and Aston Villa is that they have struggled to keep clean sheets regularly, and as a result, they have been giving up too many chances to their opponents. This has led to a high number of draws and losses for both teams, despite their good attacking form.
One reason for Everton and Aston Villa's poor defensive performance could be due to their lack of depth in the squad. Both teams have relied heavily on their top players, such as Jordan Pickford and John Stones, who have been excellent in goal and defence respectively. As a result, when one of these players gets injured or is unavailable, it can affect the team's ability to perform well defensively.
Another factor that could be contributing to Everton and Aston Villa's poor defensive record is their inability to deal with set-pieces. Both teams have conceded a lot of goals from set-pieces this season, which is a worrying trend that needs to be addressed.
In conclusion, while Everton and Aston Villa have shown promising attacking form this season, their defensive performances have left much to be desired. The team needs to focus on improving their defensive record by adding more depth to their squad and dealing with set-pieces better. Only then will they be able to compete with the likes of Chelsea and Manchester City in terms of defense.