Are you saying the facilities don't play a major part in a Bird's design and a fundamental mechanism to actually make in production?
You think these industries are cheap and unsophisticated that any country can build or allow other nations to use like they were planting so much corn?
China has decades of experience producing -many times shitty- birds before it got to this stage where it can evolve into improvements and entire new designs. Where is Pakistan's experience in this regard because there are no shortcuts? As I said again pilots don't design aircraft, aircraft designers do.
What pakistan can do is learn the process and specialize on some small sub components, like cockpit design, weapons layout but as far as producing a full fledge advanced bird from scratch not going to happen. All the 4 majors powers I outlined before both have the experience in Aircraft design as well as the multi billion $ facilities to finalize a production bird.
Don't think you are always right
As well,CAC learn a lot from the experiences of PAC too.
Have a look at this interview
"Fierce Dragon" Development and Future - An Interview with the development of aviation products, CATIC Minister Li Pei print subscription refresh
google translate
Up to now, most of the world military aircraft development projects must rely on state funds, so called government projects, and there are few investment projects by enterprises. Xiaolong is Central Air Industrial Group and its subordinate units at their own expense, and to introduce clients to invest in China and Pakistan, a 50/50 partnership program, to achieve a military aircraft development model innovation. As the aircraft industry and the customers using their own funds to develop a foreign military aircraft, Xiaolong probably the same as the K8, the extensive use of foreign clients, and then equip the Chinese army.
Furthermore, the Air Force through the partnership with Pakistan-based cooperation,
Pakistan side has provided a lot of useful experience to the Chinese side to bring a lot of new concepts and ideas, but also help China to complete the development of many aviation products. Interview, Pei told reporters that the future military and trade business, can not remain in the level of Xiaolong, China Aviation Industry Group may wish to have more and better products to obtain export licenses, and CATIC also will work to push them to the world; of course, more advanced models will also face more intense international competition. China is rising, the need to protect their strategic interests in the international arms trade with other aviation market power on the ongoing competition, and not allow such aircraft F-35 fighter jets to dominate the international market, the industry generally believe that China needs to develop a Xiaolong successor model to compete with them. Pei said that if China's future development Xiaolong's successor, hoping to continue the successful model Xiaolong.