The Maryans and Guptas were not short lived, they lasted for almost a thousand years. Must longer than the Khiljis and Tughlaqs, which lasted barely a century East. And all of those Empires were either Central Asian, Arab, or Turikish, even if they employed generals from ondern day Pakistan. With the exception of northwest-India falling to the Khushans temporarily(And once again, the Khushans were Afghan) India has never been invaded by and Empire indigenous to Pakistan, whereas most of Pakistan(and parts of Afghanistan) were ruled by a Bihari-based Empire for at least a couple centuries.
And yes, Maratha rule of Pakistan did not last long. My point is they put a short end to most of the Muslim Empires ruling modern day India. When the British arrived, they had to defeat the Marathas to control India, as the Mughal "Empire" was only a city-state in Dehli, and it was ruled by a puppet ruler who paid tribute to the Marathas.
Wrong. Ten years after Panipat, the Marathas regained control of North India, and the Durranis were pushed back to Pakistan. And the Mauryans and Guptas remained major powers combined for almost a thousand years. And it is proven Chandragupta Maurya was a Bihari born in Patilputra. And only small kingdoms(Hindu and Muslim) paid tribute to the Mughals. Significant Kingdoms such as Vijayanagar never paid tribute to anyone, and forced Muslim kingdoms(such as the Bahmanis) to pay tribute to them.
Nothing you said changes the fact that
1. For most of the past 10000 years, India was ruled by indigenous empires(Including the British, for only about 500 years was the entirety of India under foreign rule.
Although India was never ruled by an indigenous Empire native to Pakistan(with the exception of some Pashto Empires like the Durranis if you want to count them as Pakistani, but their rule never lasted long), modern day Pakistan was ruled by Bihari Empires for centuries.
If that were true, you would expect there to be some prominent Sanskrit literature from modern day Pakistan. but all you have is unproven claims to the Vedas.
THIS. Alexander only saw a small part of the subcontinent before he was forced to turn back by the Nandas, so his accounts are not valid. The most accurate descriptions of Indika, the origin of India, were written by Megasthenes during the Maruyan Empire, which was based in Patilputra.