It’s silly to think differences among groups dont exist. That isnt to say that every, say, satmerer is the same or that they all follow every carecteristic of the group. Butit is equally foolish to say that in spite of them having a certain shitah, living together, haing their own school system etc… There is nothing that combines them together as a group. Of course there is. For example. As a group Satmar opposes the Zionism, that does not mean that EVERY Satmerer feels that way. But if you meet a Satmerer Chasid it isnt “groupist” to assume he didnt say Hallel On Yom Haatzmaot.
Admitedly there is a fine line between the above and being anti said group. But there is a line