I doubt Xabi Alonso's Leverkusen can dominate the Bundesliga next season. Leverkusen cannot win the title by going undefeated for a whole season. If Leverkusen wants to dominate the Bundesliga next season, Leverkusen management should definitely try to strengthen their squad. We saw the Napoli team dominate the 2022-23 season and win the title. However, last season we saw this team finish tenth in the table. So Leverkusen will have to play very carefully from the start of the season if they want to win the title.
There won't be too many expectations from Bayern Munich next season. Bayern Munich have a strong squad but new coach Vincent Kompany is not experienced enough. I don't know why Bayern Munich have appointed such an inexperienced coach.
Actually difficult for Bayern Leverkusen defend their Bundesliga trophy next season because will participants in Champion League, huge pressure and get more busy schedule matches for Leverkusen when playing in Champion League than this season their performance only participants in Europe League. But looking the other teams participants or bigger candidate winner team Bayern Munich not really difficult become competitor for Bayern Leverkusen, appointing lack experience manager Vincent Kompany seems make Bayern Leverkusen has bigger chance for defending their Bundesliga trophy next season.
In my opinion, Bayer Leverkusen has bigger opportunity percentage for defending their Bundesliga trophy than Bayern Munich and I think Xabi Alonso keep continues impressive performance with Leverkusen next season by winning back to back.
Recently Bayern Munich more active for signing new players than Bayern Leverkusen but Xabi Alonso keep with their current squad seems not need new adapt just several players only signing right now.