There is nothing impossible for Stuttgart to become champions in the Bundesliga this year, if I see that Stuttgart has been quite consistent in playing the last 7 matches. Even though they have experienced 1 defeat, apart from that, Stuttgart has a player who is quite consistent in his game, namely Serhou Guirassy as a striker, and has been the top scorer in the last 7 matches. I think Stuttgart will enliven the competition in the Bundesliga in fighting for the title this year, although it is still too early to draw conclusions now.
Compared to Stuttgart I am more confident in Bayer Leverkusen as one of the challengers of the champion this season. Bayer Leverkusen has not been defeated so far in all competitions and Alonso has become the most important part of this victory. The young coach knows to place the right formation during the match and almost all the strategies he uses are running well until now. For me the chances of Bayer Leverkusen are far greater than Stuttgart and what Bayer Leverkusen needs to do is still playing consistently so that they are not defeated in several matches forward.
Stuttgart could have been one of the Bundesliga title challengers this season, but it would be quite dangerous when some of their flagship players were injured, while Bayer Leverkusen players were far more stable and they had a pretty balanced squad depth between core players and backup players