Re: Ancestors of Pakistanis were NOT Hindu!
Apart from historical perspective let us look at all this from the angle of racial and cultural affinity also. Here I will comment about Pashtuns, Baluchis, Dards, and Potoharis.
Ethnically, Pashtuns are an admixture of ancient Aryans ( whose modern offsprings are the mountain tribes like Wazir, Mahsuds, Daurs, Afridis, Orakzais, Bangash, Khattaks, Shaitaks, Jadran, Zazis, Mangals, Chamkanis, Toris, and Barkis...all these tribes are called Karlanis and probably their ancestors formed Pashtun proto-ethnicity..), Sakas (famous tribes like Yousafzais, Abdalis or Durranis, Mohammadzais, Marwats, Momands, etc.), and White Huns (Khiljis or Ghiljis, Lodis, Suris, Niazis, etc....called Matozais).
Many Pashun tribes got settled in Punjab e.g. Niazis of Mianwali, Khattaks and Yousafzais of Attock, Khwaishgis of Qasur, Khakwanis and Durranis of Multan, Kakaizais of Lahore, etc. In fact Pashtuns have lost many tribes e.g. Lodis, Soris, Niazis, etc. So Pashtuns contributed to Punjabi ethnicity, particularly to its elite classes. But this was not just one way traffic.
I and my friends have wondered for a long time why the artisan classes among Pashtuns of Charssada, Sawabi, and Mardan plain i.e. Peshawar Valley are black/tane colored and have very high i...ncidence of black eyes and almost none of green, brown, or blue eyes. Later we discovered that theey were not originally a Pashtun stock. Probably, they were either an indegenous people whom Pashtuns conquered and assimilated in their ethnicity or migrants from Punjab that took over the non-martial professions (like carpenting, cobbling, etc. ). In original Pashtuns, on the contrary, rose-white color is rather the norm and black color an exception; some Pashtuns also have tane color. As for eye color, most Pashtuns have brown and green eyes and many blue...black eyes have a low i...ncidence among Pashtuns. Tempramentally also, original Pashtuns are more assertive than the artisan classes. Whatever, these classes have added color and beauty to Pashtun race and Pashtuns are proud to have them as an important element of their ethnicity. Their present generations are rising to high places in existing social order.
As for culture, Pashtuns so far had a tribal social culture and values. The tribal social structure is fastly crumbling thanks the modern modes of communication, production, and politico-economic relations. Their values are also changing, some being transformed, some reversed, and some new created. Pashtunwali, an ancient tribal code, carries the essence of their culture. In traditional Pashtun Society, Islam has played an important role at social level (but not at political or economic level). So Islam is one part of the ideological culture of Pashtuns other elements of which have been drawn from Pashtunwali. The material culture of Pashtuns has a distinct form probably different from that in Hindustan. In food, dress, household culture, etc. they have different preference. Pashto is an East Iranian language closer in linguistic affinity to languages spoken in Pamir e.g. Wakhi, Yadgha, Yazdghulami, Yaghnobi, Parachi, Ossetian, etc. Before conversion to Islam in 11th Century, Pashtuns practiced a variety of religions including Paganism, Zorostranism, Bhudism, and probably also Hinduism. My own ancestors were fire-worshipers (being Gabres).
Baluchis are also an Iranic people with a tribal social structure and speaking a Western Iranian language. There are divergent claims about their ethnicity but they seem to be descended from ancient Medians, Parthians, or Sakas. Probably they practiced Zorostrian religion before Islam. Their physiogymy is also different from Hindustani people.
Dards are the inhabitants of Chitral, Gilgit, Indus Kohistan, Kashmir, Hazara, etc. that speak languages neither part of Iranian nor Indian sub-family. Physiogymically and complexion-wise, they are closer to Pashtuns but in social structure, values, and temprament are a bit different than Pashtuns and Baluchis with emphasis on industry than martial traditions. They also probably practiced Bhudism, Zorostrianism, and Paganism befor Islam reached them.
Potoharis are another ethnicity of Pakistan that are markedly different from mainstrean Hindustanis. Among the people to the east of Indus, they are the least Indianized, although they speak an Indic language. Unlike Pashtuns and Baluchis, they have a peasant social culture. Their material culture is also like Dards, Pashtun, and Baluch people with Shalwar-Qamis, unlike Dhoti, as the dress. Their villages give a different feelings than the rest of the Punjab (beyond Jehlam) and they construct high-walled houses unlike the open houses in villages to the east of Jehlam. They are a simple people and have martial traditions. Their color complexion is also different. I don't know what they practiced before Islam.
Anyhow, at present Pakistan seems to be a conflict zone of two civilizations and two streams of ethnicities; the Parso-Turkik-Arabic Civilzation and Dardic, Pashtuns, Baluchis, and Potoharis of the NorthWest with center of gravity in Middle East, Persia, and Central Asia; and the Indic Civilization and Punjabis, Muhajirs, and Sindhis of the Southeast with center of gravity in Gangtic plain. Islam is a Middle Eastern religion but Urdu/Hindi is the language of Gangtic plain. Would the Potoharis, Baluchis, Pashtuns, and Dards pull Muhajirs, Punjabis, and Sindhis towards the West away from the center of gravity of Hindustani Civilzation or would Muhajirs, Sindhis, and Punjabis pull Dards, Pashtuns, Baluchis, and Potoharis away from the Middle East/Persia/Central Asia towards the east....Or would a split occur with Pashtuns, Balluchis, Dards, and may be Potoharis not willing to be desolved in the great melting pot going their own way...?