The outside enemies don't matter at the moment. I doubt the people would rather having a government that leeches off all of their wealth and living standards, than a foreign government.
At least India somewhat cares for their people, be it a communal sh1thole or not, which is more than can be said for this Junta establishment.
If you want to speak from the perspective of the people, breaking up does not matter. It's likely that we'd be more efficient in making smaller separate nations, than the current state of Pakistan and the people would be more likely to be fed, which is the biggest issue at the moment.
The biggest threat to India lies in Pakistani Nukes. India's current interests lie in taking Kashmir, which they can gladly take. I doubt they would want anything else from Pakistan, except perhaps Karachi, which can be bargained to stay within Punjabistan in return for not firing a bullet over Kashmir
And how on earth does NaPak fauj benefit from a splintered Pakistan? It looks like the main way that the hegemonic force would be destroyed