Yeah we can't ignore the fact that Gyokeres used to play in the Premier League but during this period his performance was not optimal and now he is back with Arsenal even though we know he has the ability, we can't be sure whether he will be able to adapt quickly. Arsenal have spent 65 million to bring in Gyokeres and 2 other expensive players which has spent a total of 224 million which puts Arsenal in the top 3 with the most spending in the transfer window (EPL version) well, we hope that what they spend will be commensurate with their performance next season.
It is true that Gyökeres struggled in Premier League before so even though he has been great in Portugal we do not know if he will succeed in England this time. Huge amount of money Arsenal paid for him and other players puts much of pressure on them to perform well right away. Everyone hopes that all this spending will lead to better team that can win championships. So we will just have to wait and see if these new players are worth money and help Arsenal reach their goals.