I agree with passage of time, we have become more similar to pure Indic Bengalis and we proudly say we are Bengalis but I was trying to refute your compatriots statement who said part of Indian civilization which we are not.
As I said we came at 12th century and frankly speaking the fragile Indic Bengalis couldn't even put up a fight. Are you interested in knowing how we conquered the entire Bengal in the first place...???
That old Indic fool Ballal Sen didn't even dare to fight and escaped on a donkey's back while trying to fix his dhuti after he heard about the approaching Arab General Bakhtiar Khilji.
Such is our legacy. Okay let me put it this way, we came, we saw and we conquered!!!
I think our ancestors expected a better show from the Indic Bengalis... but they proved to be a disappointment.