I think it's the new manager syndrome that helped Leverkusen in the previous season, he came with not only a good strategy but some most teams couldn't understand but it seems several managers took their time to study his strategy and that's why it became tough for him to repeat the performance of the previous season. Well, I didn't expect Leverkusen to be unbeaten in two consecutive seasons, that's some that we don't normally see in modern football and even tough for most top managers to do, I don't even think Leverkusen would win this season's Bundesliga title though they might finish in the top four and qualify for the champions league. Bayern Munich are more favourites to lift the trophy and it's gradually becoming a reality cause they'll the only team in the Bundesliga that's yet to be defeated, they play much more better and different from the previous season and I believe they'll reclaim their trophy and become dominate in the league once again.
I agree with you on this, when a manager that has good managerial skills arrived at a club, he will perform very well with his team because it's assumed that other team may not be conversant with his new pattern of play and that will make it difficult for other teams to tackle them but such manager should not expect business as usual in the next season, what we are seeing in Leverkusen presently was expected to happen, though I didnt expect their performance to be this bad to the extent that they were unable to beat teams like bochum that is not in a good form, bochum was beaten by Bayern munich convincly in the previous week but bayerleverkusen allowed them to equalized towards the last minute of their match with them, in the last 5 matches of Leverkusen they were able to win 1, draw 3 and lost 1 which was in the UEFA champions league with Liverpool, they match ended on a 4:0 defeat against them, i have thoroughly cross check their performance, it's very unimpressive.
Talking about their chances of winning the league title this season, their chances is very slim because I don't see any seriousness in the team, so how are they going to do it, unless theirs a change in their performance, if not there is nothing they can do, they have made it so easy for Bayern Munich this season, as it stands I don't see any form of obstacle for Bayern in that league, so it will be easy for anyone to conclude that bayern will be the title holder this season considering their performance.