maybe in late 40s.....but today you have Baloch working in Punjab, Sindhi working and residing in Balochistan; Pakhtun in Karachi Sindh; Punjabi tending to business in Khyber-Pakhtunkhwa; Kashmiri Pakistani serving his nation in uniform in Okara; or Chitrali running business in twin cities.....Pakistan is very much one nation.
and it's bizarre coming from indian b/c you dont even have a national language to unite your country the way we do.....we dont have rivalry the way you have north vs. south or east vs. west . According to your logic your india is probably 487 nations
so much for "raison d'etre"
p.s. in Iran you have Persians, Kurds, Azaris, Arabs, Balouch and other groups......"Persian" isn't one nationality. Same applies to a country like Turkiye; you have Lorz Azeris Armenian-Turks Greek-Turks Black-Sea Turks, Macedonian Turks, Arabs, Kurds . . . . all these people together comprise these great nations.
hope you got my point