Arteta has actually made good preparations with their second tier players since last season. And actually Arsenal has also succeeded in minimizing injured players in their team. It's just that I think this team still lacks motivation and developing a better player mentality.
This team tends to only focus on one competition. And when this team has several competitions at once, we can see the quality of this team decreases. But when this team started to focus on one competition, this team started to improve again. So I think this team should learn from Manchester City, where they always managed to maintain their performance during their best times even though they were busy with a lot of competition.
Arsenal has also moved quite aggressively in the transfer market. So I think Arsenal can improve. But I personally prefer not to expect too big a return. because I don't want to be disappointed again.
This is exactly were squad depth comes in, you can't constantly play your first team in every competition, it makes your players more prone to injury. There are some stages of competitions that you need to field in your reserve for them to do the job with just 2 or 3 senior players for guidance. Early stages of the FA cup where you get drawn to a lower ranked team and the EFL cup. The reserve players can handle this while your first team players takes a rest for that week.