Nawaz Sharif is Pakistani (I donot say others are not pakistanis) , he has benifits from a stronger pakistan, his Factories will run smoothly then , His Farmers will give more returns then , His lands will give him more corps then.
That is why he would see Pakistan as stronger, progressive and Prosperous.
Altaf Have already setteled in UK and others will also give him fring benifits,
Zardari is no different then Altaf , known for Dubai and USA.
This is the core difference among them.
This does not imply that Nawaz Sharif is not corrupt , but , at least He would never compromise on Larger National Interests like the others did and settled abroad.