You see when it comes to Offense m Nuclear weapons are already way too offensive. Infact Offense is a loose term, MAD is the most precise term.
MAD , with MIRV or No MIRV , when it comes to launching missile, you will be sure that defeated or not defeated ( the BMD systems ) the response will be Massive.
So you see my freind, When it comes to Offense aka MAD its not a very good situation for Pakistan. Coz it means mutual suicide.
Now, Look at India, though they have had ALL the resouurces for MIRV they are not focusing on Offence, rather moe on SAMs , BMDs aka Defence.
BMD are practically useless for China. ( which is far far far far more sensible nation than Pakistan )., but with Pakistan so close, Im damn sure our BMD can do some serious damage ( which is proven by the fact that Pakistan ACTUALLY ( Hins : ISPR Press Release ) considers Indian BMD to be effective against NON MIRV missiles of Pakistan )
The point being, in Boost Phase, MIRV or No MIRV will not make ANY Difference. Since Indian radars AWACS can and are tracking the ENTIRE Pakistani Airspace !
Before any one dares comment on "EFFECTIVENESS of a BMD" , plz stay assured that the Usage of Indian BMD and its effectiveness will be of far less importance ( in Pakistani Perspective ) when its Use comes to a REAL Nuclear Exchange ( If 10 Missiles from Pak are Fired , 9 are Intercepted , and even if 1 Hits , Indian BMD is STILL a Success, while It will GURANTEE a rain fall of 100s of Nukes in Retaliation from SSBN Subs and Mobile Launchers ! )
There is a SOLID reason why we have a NFU. Its an Excuse to Wipe out our Adversary !