There is nothing wrong to admit that we are different races, we need to come out of this false notion that it is wrong.
Pakistani race and Bangladeshi race are completely different, it is apparent to anyone. We have not much in common except we were on polar opposites of a great Muslim empire and one British India one.
Most Pakistanis are Iranic by race (Scythian, Parthian, Hephthalites) with a large mixture of Turk-Mongol (from Ghaznavi, Mughals, etc.) and some Arab (Muhammad bin Qasim's forces) who mostly replaced the Indo-Aryans and Graeco-Bactrians.
Our geographical heritage and part genetic hertiage, before migration of Iranics, is that of the Sindh river (Indus). In this way we were connected to ancient empires of Babylon, Persia, Greece, etc.