Leverkusen and Dortmund teams may finally try to win the title. The Bundesliga will be even more competitive this season than last season.
I will agree with you that football is full of uncertainty but in the case of Bayern Leverkusen this season, the team is looking so strong in terms of performanc even though they are not in the middle of the season yet but they can still go all the way to surprise the world by winning the German league this season. Dortmund is not strong to be compared with Leverkusen or Bayern Munich this season and they are not in better shape to win the league this season I think the title will be between Leverkusen or Bayern Munich.
Comparing the performance of Leverkusen to that of Napoli last season I think Napoli started very well from the beginning of the season and they maintained the winning streak till the middle of the season till they were officially declared winners last season who knows if the same thing will be seen this season in the German bundesliga but until then I agree it is too early to pick the team that will win the league.
Bayern Munich still has a chance to win the title this season and Bayern Munich is only 2 points away from Leverkusen so it is true as you say that the strongest candidates to win the title are Leverkusen and Bayern Munich.
Yes, it could be that Leverkusen will Napoli be like last season because so far Leverkusen hasn't lost, but still comparing the two is quite different because they have different squad depths and we also don't know Leverkusen's next performance because it's still early in the season and Leverkusen still has a lot of matches to play in the Bundesliga.