Do you really think that nuclear scientists will approach Pakistan? Or that USSR will sell their technology to Pakistan for money? USSR dissolution was mainly about splitting of industrial base of USSR amongst the new countries. For example, some countries like Ukraine got Antonov factory, countries like Yugoslavia got factories to make some other heavy equipments etc and as a result, no single country had all the infrastructure to make proper weapons. For example, Russia could not make transport planes because of Ukraine having the antonov factory whereas Ukraine had no other industry and hence could not do anything else. All the countries that split from USSR did so after USA assured them of soft loans and hence they did not have funds deficit. The problem was not with funds but with industrial base. Only those countries like India, China, which already had industrial base, managed to gain somethings from USSR. India, China offered their domestic industry to help Russia get equipments and parts for their weapons and in turn USSR allowed India and China to have full license to manufacture all the items which was jointly produced. India offered HAL, which already had ability to make MiG21 to develop Su30 and hence India got Su30 technology as return. It is unlikely that Pakistan could offer anything meaningful to these countries to get any technology during 90s.
Yes, Pakistan could have developed technology and its know how earlier itself. But Pakistan never industrialized. Pakistan did not have enough technical manpower and never had enough engineers and scientists to form large base of scientific community to start new projects. Pakistan was indeed close to USA but that does not mean that USA will spoon feed Pakistan. For example, Iran was also close to USA but Iran managed to get several technology and even developed a small industrial base with USA support. Iran then used it after revolution to get some amount of indigenisation. Pakistan on the other hand, did not even think of developing any industry and never tried to develop enough skilled manpower for industry.