Well, same argument can be said bout you too... first build even a scooter engine, let aside something as complex as a MIRV. Don't want to get into pissing contest. Lets stay on the topic of discussion.
Since you are quoting a US Govt. document, while we are talking about an Indo-Pak scenario, so you are assuming as well, that your capabilities are equivalent to the threats faced by US (i.e. The Russians, The Chinese, maybe NK). I hope you are serious there, because I can merely laugh at your assumption.
Indian BMD program, even if flawed, will provide certain capability(maybe 30% - 50% intercept probability), will dent your capability for a MAD. I.e. to say that you will need more warheads and delivery systems to assure MAD or you can improve upon technology both in terms of warheads and delivery platforms to evade Indian BMD, and both will cost you additionally.
Now, its the cost, thats the real weapon that India is using against Pakistan, we have forced you to increase expenditure on your Nuclear capabilities. We have forced you to have submarine based Nukes, as the efficacy of land based systems have become questionable due the lack of strategic depth. meanwhile you keep on cutting budgets for other conventional acquisitions like twin engined fighters, advanced subs, destroyers, ASW platforms.
And all that expenditure, on something, that you will you use only when you have no other option than a suicide. Because once the nuclear exchange begins, there is no saving for Pakistan due to smaller size.