Maintaining the squad is indeed one way to be able to maintain their consistency for next season, because if they continue to change players then it is difficult for them to maintain their consistency. Because basically Bayer Leverkusen is not an elite team, so with finances that are not as good as Real Madrid, it is at least difficult for Bayer Leverkusen to maintain many of its key players. But indeed, considering the way Real Madrid always has young players who are willing to stay in the team for a long time,then Real Madrid also manages to have a good performance every season, because the team has a good chemistry. Therefore, if Bayer Leverkusen is able and successful in retaining its key players then ofcourse, Bayer Leverkusen has a chance to still be able to play well in the next season.
Leverkusen's players have performed very well this season and Leverkusen certainly wants to retain their players and has no intention of selling them and even bought players to replace the roles of players who have contributed greatly to achieving this season's achievements. Xabi Alonso still wants players who are the goal is to stay afloat and provide strong competition again for next season because Leverkusen wants tight competition in the domestic and international leagues, especially since Leverkusen will play in the Champions League next season and Leverkusen needs strong players so they don't make mistakes.
Indeed, when the club is on the rise, the players will definitely be targeted by big clubs and it will be quite a difficult choice for the players whether they want to stay or leave the club and move to a bigger club which is of course more convincing and Leverkusen is at a different level to Real Madrid, unless the players are willing to stay at Leverkusen because of their very high loyalty and solidarity, then Xabi Alonso will be safe because Xabi Alonso does not need to make a major overhaul, only needs to add one or two players to improve their performance next season.