Yes many Pakistanis identify themselves as Muslims first and so do some Saudis, Kuwaitis, Iraqis, and Iranians.
We are taught in our religion that as soon as we enter our grave the first question the angel will ask us is "who is your Lord" and "what is your religion". So the only thing that will matter is that we are Muslims and how good of a Muslim we were in our life on earth.
Some Saudis, Kuwaitis, Iraqis and Iranians do! Not 6/7 of their population do!
To remain a unified country for a long, you need to believe in the concept of Pakistan. That you all are one!
Being Muslim first concept is a medieval concept used at the time of Caliphate for political reasons, just like Romans did when they embraced Christianity, but you know from history that Christianity did not keep the country united. So if 6/7 people in Pakistanis believe that, there would be political tendency to form another Caliphate. That is good and all, but who else would like to join the group?
Do you think Saudis will join, Iranians will join, Iraqis will join, UAE will join, Turkey will join, Sudan will join, Egypt will join, Ethiopia will join?? Which country feels that they want to be united with other Muslim country?
Another thing is that whether establishments wants the same. Saudi King wants to give away his power? or the Iranian Ayatollah ? or the Kurds? or the Turks?
So when neither the establishment in other Muslim countries would join to form a Caliphate nor the people in respective countries see themselves culturally similar or connecting to other Muslim country to form Caliphate, what would this evolution of Pakistanis will turn out to be?
Pakistan does not have the power to take out rest of Muslim countries by force and if neither are going to join, what would vast amount of unemployed Pakistanis do?
They would turn to create suicide bombers for rest of Muslim world to make them forcefully join the so-called Caliphate. The rest of Pakistanis will find their causes with India, US, Israel, China, Europe?
I think the government should get this identity crisis resolved.