Both teams you mention need other potential players. But Bayern Munich does not need a striker now, or let me say, it is not necessary for Bayern Munich to get any players in my opinion. because they have all the positions and they are still strong, so they don't need anything like that now.
If you think Bayern Munich don't need a striker right now, then why are they so adamant in bidding for Harry Kane this summer? isn't it obvious they are not so confident with the current squad even though everything feels very complete. Moreover, competing with other strong teams in the champions league is not an easy matter if a team doesn't have a mature striker and I think whatever the reason, Bayern Munich will still be looking for a new striker if later they don't manage to get Harry Kane.
So far Bayern Munich has 2 center forwards, namely Eric Maxim Choupo-Moting and Mathys Tel. The two attackers were played alternately by the coach and both had good goal contributions last season. I think Bayern Munich want to sign a new centre-forward because they realize that Choupo-Moting is no longer young. He is already 34 years old although he has good form.
Apart from the two centre-forwards I mentioned, the Bayern Munich coach often gives my player or the second striker the opportunity to occupy the center forward position. Sometimes that's good, but it would be great if Bayern Munich had a pure centre-forward instead of doing some experiments on wingers and others to become a centre-forward. Kane is a good fit, but so far nothing is certain.
It's true that currently Bayern Munich still have two strikers in the squad and when it comes to scoring goals I'm sure they can do it. But it needs to be underlined here that Bayern Munich want a striker who can not only score goals but they want a striker who consistently scores every season and the answer, of course, is all in Harry Kane. Therefore they don't want to take the same risk as last season which was very difficult to score in the Champions League and for matters in the domestic league I don't think Bayern Munich are confused even though they are using two more strikers.
It should also be underlined that domestic league competition and the Champions League have a much different intensity or level of difficulty. Maybe Bayern Munich in the domestic league always encounters almost the same opponents every season and they can always win every season, but if in the champions league all the best teams are in the big preliminary round and they cannot take this lightly.