That is some flawed history , as there is no connection between Mohammad Bin Qasim and Pakistan
The "region" geographic area we know or call Pakistan and it's people had had cultural ties with various empires in past
That is why our food looks like Persian food with touch of extra spices
From
European /
Persian /
Arab and
Mongol , so we have developed a good cultural mix
And never did we ever were connected to entity called South Asia
Mohammad Bin Qasim did not leave us a Trove of Gold and Dimond which we used to free Pakistan in 1947, it was work of people Muslims who wanted a Independent state
People like
Mohamad Ali Jinnah and others who envisioned Pakistan Such as
Illama Iqbal or the ground work done by
Sir Syed , who setup education and schools