I don't think Borrussia Dortmund will be able to stop Bayer Leverkusen this season because Borrussia Dortmund will have to fight again to get into the top four of the Bundesliga standings. But for Bayern Munich, it is still quite possible for them to stop Bayer Leverkusen because considering that the distance between Bayern Munich's points is still quite close to Bayer Leverkusen in the standings, it does not rule out the possibility of making Xabi Alonso's team difficult again in the second half of this season.
It is obvious you are undermining a team like Borussia Dortmund that have been around the top for many years. By their recent performance, you might think they will not be a hard team for Bayern Leverkusen but in reality, the later will have a hard time winning them. Anyways, if I'm to agree with you on something, it will be the fact that Borussia Dortmund is not in the race for the title this season. No doubt Bayern Leverkusen is determined to win the trophy this season but that will come at a huge cost and Bayern Munic will definitely make the journey rough for them. Don't forget that they are toping with just a point if Bayern Munic happens to win their one match left.
Let's just hope that Bayern Leverkusen keeps winning their games. One thing I know is that they won't end the season unbeaten, but even if they are going to lose games it shouldn't be now.
I agree with you on this, there is no way they will not lose any match because they will be a little busy with the European competitions when it gets tougher and coping with the domestic league will pose as a serious challenge. Let's see how things turn out for them and if they prepare some surprises for the world this season.