Yes indeed, although Galatasaray managed to beat Manchester United but of course, it does not mean that Galatasaray will be able to beat Bayern Munich too. Because after all, Bayern Munich is basically the team that can certainly win Group A, considering the previously predicted competitor team is Manchester United . But in fact, Manchester United have had poor results in the group stage so far and therefore, Galatasaray will surely look to maximize this situation to become the runner up of group A.
Bayern should not be compared with Manchester United now, the Red Devils have many internal problems, this affects their results. Galatasaray will not be able to beat Bayern, but it may well score 1-2 goals, because Bayern's defense is not in the best condition right now and they still do not have a reliable goalkeeper in whom they can be confident, but the same goes for Galatasaray, they concede a lot of goals and I think Bayern will be able to score two or more goals.