Not only defense, Newcastle must be able to bring in some star players on all fronts, money is not a problem for Newcastle, because the club owners are ready to disburse funds to sign new players. Newcastle must be able to provide competition at the top, to compete for the title Newcastle have to wait a few years for their squad to be completely complete. While being able to rise in the top four is enough for Newcastle, because the Premier League competition is very tight to compete for the title.
Newcastle is the richest club in the world right now, so whatever he wants, even some of the best players can buy him especially in defense which I don't think is very good.
and it took quite a long time to build a solid and compact team into a very good team and able to compete in the top teams in the EPL, and there should be significant changes in the next season and we'll see what changes will happen with Newcastle.
I believe they will make big changes in the team because they have the money to do so. I also hope that the performance will be a lot better. I obviously don't think they will suddenly finish in the top four or anything but I believe there will be significant improvement considering that they will surely buy a lot of good players. they should be buying players for both defense and attack.