I don't think think you understand basic math, 50 kilotons is on the smaller end for modern nuclear bombs but it will still devastate any major urban center, also in the case nuclear bombs there's diminishing returns, a 100kt bomb might have double the yield of a 50kt bomb but does not mean it will have double the blast radius, to double it you require roughly a 400 kiloton warhead.
I thought you being "rocket man" Here would understand this basic concept.
Sure, blast radius does not scale linearly with yield, nobody is disputing that. But larger yields are not just about “more city damage per kiloton.” They give you more coverage, more tolerance for CEP and targeting error, and a better chance of destroying hardened or spread out targets even if the strike is not perfectly accurate. That is exactly why larger yields still make sense for counterstrike roles against nuclear complexes and other high value infrastructure such as hardened missile silos , sub bases which for India and Pakistan are few or barely non-existent.
The most critical factor in the India-Pakistan nuclear dynamic is distance in that most targets are within 4-8 minute flight times for both countries. No early warning as such matters here - then take urban density - Dallas Metro is 3500 people per square miles on nearly 9000 square miles of land on which means to really make an impact in Dallas you do need hundreds of kilotons and possible several to effectively destroy the area.
Meanwhile, Greater Mumbai is only 233 square miles but 76000 people per square mile(about 2.5 times Dallas) - which means a 50 kiloton warhead will vaporize much more than the many hundred kilotons needed for Dallas.
Then there is the counterforce argument - because of the mobile nature of the systems on both sides in general - any counterforce relies on near perfect intelligence and Pakistan has been practicing rotating its nuclear assets since 1980. Even if post 1 exchange India decides to go for a full decapitation strike, its best bet is to hit Islamabad with the shortest flight time and with massive firepower so that any leadership bunkers are also evaporated.
Anything barring that and Pakistan hits back - India not only ceases to exist as a state but also the overall firestorms from densely packed cities, infrastructure and so on basically create nuclear winter globally and for the subcontinent with general weather patterns blowing west to east(other than winter monsoon) even the strikes on Pakistan continue to devastate whoever is left alive in India for decades if not a century or more to come.
The reason I state this all is to show that weapons sophistication and yield matter much less when you both can hear each other breathe and fart.