Recruiting more is not a guarantee if in the end Arsenal's pattern remains the same where their winning mentality is not well formed so that what they do including good performance at the beginning of the season as they always do will slowly erode and decline when Arteta is unable to maintain consistency.
Previously, Arsenal also had some good recruits, but still, they still couldn't do and get the best results. It's not easy to compete in the Premier League, but Arsenal has the same pattern, their achievement is "close to win the EPL, but again failed." and this has happened for years.
In this transfer market, Arsenal actually only needs to get something much better, not more. And now, Arsenal have met with Martin Zubimendi in London, to do a done deal. Real Sociedad's release clause is €60m.
I still find 60+ million a lot for Zubimendi, we are talking about way too much for a player that doesn't deserve that much money. But Real Sociedad knows that they are in it for the long term and need the money and Arsenal can afford it, whereas the situation, Arsenal is in is a tricky one because for three years they have been a second place team and the whole "always the bridesmaid never the bride" thing is getting a mockery from the fans not only from other teams but starting to be from their own fans too.
This is why they are not afraid of spending a bit more than they should, because they want to be the first place. Gyokeres was a situation that took too long and Sporting made a mistake, that has to be the most careful place.