Bayer Leverkusen is one of the clubs that opponents fear in the Bundesliga. Not all clubs can beat Laverkusen easily because they were at the top of the standings last year with good performance. It would be really good, as you said, that Laverkusen should add several senior players and star players, especially strikers and defensive midfielders, so that they can be more confident of winning this season.
I don’t see anything wrong with this squad and they can still fo wondrous things also this season. Adding more senior players to the team will really help them but I don’t think it’s a necessity now that the league have started and they started on a good course. Bayern Leverkusen still remains one of the strong contender for the Bundesliga title this season and without putting that great performance together, they will not be able to keep that consistency of wining the league again. Many clubs should fear them but i don’t think they’ll get it easier as they did last season. The league just started but they can’t keep the unbeaten streak this season after losing their most recent match, that shows how tough this season is going to be for them.