I don't know where is it coming from, but do you think Pakistanis cannot even do that math by ourselves? Do you have some personal prejudice against Pakistan? Developing rocket model isn't an issue at all in solid propellant domain. If the resources are available, even a novice engineer can come up with reasonable rocket model after a few trials. Regarding Nukes: Though they blame Pakistan have transferred the technology for centrifuges but who knows? Maybe we're crazy but we're not crazy enough to transfer blue prints for nukes - that would ultimately become irrefutable proof of nuclear proliferation. Also, for your information, Pakistan have nuke with yield 25 KT to 400-500 KT and that are not H-Bombs.
PS: Don't confuse yourself with state of art navigation, tracking, communication, flight control and other sensors. There are only a few countries capable enough to produce them - the rest either buy or smuggle because they're to much complex too copy.