Losing 13 points early in the season is indeed a bad thing, but they can quickly find the rhythm of the game that can bring them back to victory. Also they can still be said to be lucky, because at the same time Bayern Munich also lost 9 points from the matches they have played in the Bundesliga.
The distance of 4 points is not too far, so they still have a lot of opportunities to be able to reclaim the top of the standings, with the note that they must be able to play consistently and while hoping that Bayern Munich slips.
Losing points early in the season will not be a problem for Leverkusen as long as the current points gap is not too far. We see that the current points gap is not too far and only enough with 2 wins and 2 losses or 2 draws from Munich, Leverkusen can shift Munich's position. However, this is not too safe and as long as Leverkusen's performance is still very consistent and also still with Alonso, I am sure Leverkusen is still a very terrible threat to Munich. I hope this competition will continue until the end of the season to provide a very interesting sensation.
Of course Leverkusen will still be a threat to Bayern Munich, because after all this team is the team that managed to make them lose the Bundesliga title for the first time after 1 decade they managed to defend it. In addition, Leverkusen also does not have many changes in the line-up and they are still with the same coach who last season led them to become champions in the Bundesliga. That means Leverkusen still has the strength and capital to do the same thing, even though at the beginning they slipped, but it was not a big problem because they were able to return to their proper performance.