We need realistic approach ...
In light category we have JF-17 and upcoming block III will outmatch all birds in Light category , 200+ of them will be enough for all Migs and Jags and M2Ks of IAF.
Does PAF need One new Medium Fighter ? Yes PAF need one, F-16s(No doubt that they are best in there category ) are getting old (majority we have are old version only few are New block-52)and they are sanction prone and what not,,,, We have to let them go one day. We also have to retire our Mirages (We can not change and replace all of our birds with JF-17 or I would say with One Bird), so best Option if we look closely is J-10P(P stands for Pakistani version). There induction not only allow us to replace Mirages (delta with delta ) but also give us 40+ years of peace of mind in there category. Second best option is (was) M2K I guess we missed that train already.
Does PAF need heavy 4.5 Gen bird ? Yes PAF do need one , for deep strikes and for Seas , Best options are EFT , Su-35 and J series from China. If Money can be arranged then EFT is the best among all (if available) , There are more countries involved in EFT programme and all of them are our allies , and our best ally counties also using that bird , so sanction wont be that effective plus that bird can help us in Our Next Gen Bird program and in JF-17 program even in J-10 if we buy them, Russian Bird (Su-35) is also great but can we trust Russia on that??? Then China's J series that also have issue with selling to other countries.
For 5th Gen , We can work with Turkey and China on different options , meanwhile we can buy (if pocket allows) J-31 .......
In short , PAF need more birds in 2 categories which are Medium and Heavy , We already wasted many years I hope we don't waist many more.