contrary to this, it is unlikely that sevilla can afford any major signings with the clubs financial standing and yes, getting champions league football does not change that position. it is left to see if sevilla are able to get quality loan signings, else they would struggle with relegation like the just concluded season
It's difficult to fight in the Champions League when a team doesn't have high-quality players, but in the season that just finished Sevilla were still able to stay in the middle area of the final standings and it's not that close to relegation. But for next season Sevilla will have to fight even harder because they are already in a tougher competition apart from La Liga, because the Champions League is a league for the best teams from several domestic leagues.
Having good players and good positioning, and the players doing well in their positions, especially the midfielders, as you noted, are some of the fundamental principles that Guardiola employs. Additionally, based on what the other user said, Sevilla seriously needs to improve its financial situation before the clubs suffer more harm than they already have—they even struggled to earn 49 points—before the clubs become more damaged than before. I hope they invest in new strategies and more players. since other clubs are busy working to improve the performance of their clubs.