Actually, pinpoint accuray is not that important for a nuclear weapon. Even if they miss by 10 meters or even 100 meters, the destructive power of the explosion will wipe out the city. Nuclear weapons are area weapons, meant to vaporize a large area. So if Pak shoots a nuke at Mumbai, or India shoots one at Karachi, missing by a hundred meters or so makes no difference. The circular error probability of modern ballistic missiles is only in the range of tens of meters.
The advantage of nuclear tipped cruise missiles is that they can be launched undetected, compared to ballistic ones. Satelites and radars and AEWACS will find it more difficult to detect them. Also, since they can maneuver in flight, they have a better chance of evading anti misssile systems. I wouldn't describe either capability as one that can change the tide of war, because for one thing, for both India and Pakistan, nukes are weapons of peace, not weapons of war. Also, neither have credible missile defence shields anyway. Or highly sophisticated satellite tracking systems.
Nukes are not going to be employed as warfighters by either country, so whether they are mounted on cruise or ballistic missiles is not that important.