Yeah, despite the level of performance Leverkusen pulled off last season winning the bundesliga trophy without losing a single league match, still, they don't match in comparison with Bayern Munich who have won the bundesliga back to back, whereas Leverkusen by way of their drop in form this season doesn't seem like they could pull such show because right now they're sitting 7 points beneath Bayern Munich and am convinced Munich isn't dropping points for Leverkusen to close in on them.
Yes, and is it possible to assume that Leverkusen were nothing more than lucky last season? I think it is possible to assume that, but at the beginning especially before this season started I really never expected Leverkusen to experience this kind of decline in performance, it means that it seems that there is something wrong with Xabi Alonso, maybe he is wrong in implementing tactics or maybe he did not make any changes to his team so that other teams know his weaknesses which makes them draw more than win, even though as you said last season they were extraordinary which won the title without losing at all throughout the season.
Bayer Leverkusen unbeaten run campaign that led to their winning the bundesliga last season wasn't anything of luck but was due their hardwork and high spirited the players were with every game played that season. Luck doesn't flow in that way recurring in straight 34 matches in a season. It rather makes sense to say that Xabi Alonso's tactics and strategy has been studied by other teams and which is what makes this season looking difficult for them repeat their unbeaten campaign.