I agree Mikel Arteta has done good job at Arsenal especially in his first season when they won FA Cup. But to make team even better they need to focus on making players feel more confident and mentally strong. Having strong mindset is very important if you want to succeed in big competitions. If Arsenal does not do well this season it will be even harder for them next season because other teams are getting better quickly. So it is very important for Arteta to help players develop winning mindset which will help them compete with confidence and do their best every time they play.
Arteta has managed to make Arsenal one of the strongest teams in the Premier League but unfortunately they have not been able to achieve better results in terms of competing for the title, although if you look at Arsenal's performance so far under his coaching, it is a bit more stable. Arteta needs to build the mentality of his players so that they can make a difference to the title and focus now on strengthening the team so that they have a better chance of winning the title. For this season it might be difficult to compete with Liverpool because they are very strong and Arsenal will face a very tough challenge against Liverpool who have been much more consistent this season.