Bayern performance is extraordinary this season and I don't think that they are scared of any club be it Leverkusen or not. Leverkusen that has struggled to pick form and Bayern has been in form since the beginning of the season. It's only if Bayern drop form and start losing their matches before Leverkusen can take over the first position from them.
Since Bayern Leverkusen epic performance last season, people now overrate that club as if they can easily overthrown Bayern Munich the way they did last season. So many things contributed to Bayern's downfall last season and Leverkusen did not failed to utilise their chance to take control. The good thing is that Bayern Munich seems to be back to challenge and take back what looks like heritage to them. Leverkusen is still second on the table but I'm not sure if they can defend themselves as the champions of Bundesliga this season.
Although, both Munich and Leverkusen performance can be measured to be in the same level but Bayern Munich seem to be more consistent than Leverkusen. In fact, Leverkusen approached the season with very average performance but I noticed they've improved their game in few previous matches but that doesn't still give them advantage over Bayern Munich.