Since Manchester United couldn't have a good performance so far during the last season now they want to improve the team and especially the midfielders, that's why they decided to stop working with Casemiro and McTominay while these two players are both key players, and effective for Manchester united but they won't stop working with both players and hire some other players instead and they think Manuel Ugarte but this player too expensive and PSG asked 65 million euros for him that's why Manchester United thinks about Sander Berge the player Burnley.
In my opinion, Manchester United should have sold any of their current midfielders as a way to complete the Manuel Ugarte deal, Casemiro and McTominay cannot strengthen the midfield as they would like, in fact, Casemiro has not been in the best form since last season, and Manchester United should have considered selling him when the Saudi team request for him because it looks like Casemiro's career has ended in Real Madrid, this isn't the same Casemiro we knew from Madrid.
They are playing base on how it favors them, talking about Arsenal, I think since Arsène Wenger left they started doing well in club friendly games, so is like they value the friendly games more and you have to see how wonderful they played ahead of next season. Seeing the Leverkusen side with all they did last season losing any game now isn't important to them until the main show get started, for now I believe Bayer Leverkusen have a lot on their plate and they are ready to keep everyone fit for the task ahead on like the Gunners who has already planned to fail on their quest for greatness. If nothing positive comes out for Arsenal then it is official that the Gunners are never going to win anything until they start spending heavily.
You're right, it looks like pre-season games are more important to Arsenal than league games, Arsenal can perform well in pre-season games but weak at the end of the season, Arsenal has to break their curse of failing to win a title. Arsenal has failed at the end of the season in the last two seasons because they can't do as well as they did at the beginning of the season, and based on what I see at this point, Arsenal will make the same mistake next season since they still have the same players as last season, they did not spend much money on getting more players to improve their performance, while Arteta refused to learn from their past mistakes.