Correct Who Knows! but Why?
Simple,
the resources we have put in Vipers, the infrastructure, tech guys, boys who fly em, years of experience. Why would we let it go just like that??
Azm is atleast 15 years down the line, plus you cannot add it in large numbers (just look Chinese & Europeans/US), 4.5 Gen fighters will be here for a long time and especially in South Asia scenario. They will accompany 5th Gen for a foreseeable future.
So why will you not procure more Vipers (if you can) to increase your 4.5th Gen fighters, operating of which you have decades of experience & excellence? Have invested so much over the years.
Until & unless USA completely kick us out, even stop our support programs for current fleet & other procured weapon systems, regard us same as likes of China & Russia in terms of Defense sales, we will go for the vipers ( already procured defence systems , not the new ones that i agree with you).
If we have something that is better technologically/Effective as as weapon system. There is new confidence that has developed after last year on Chinese tech...it has been combat proven. why we loved F-16s because it was combat proven & effective. heck we had LFK601 experiment in live/combat situation.
I agree with you here, in all my opinion of having more Vipers i never meant that Thunder/Chinese EW is not upto par, in fact i agree they have proven themselves & much more is there which is not open to public. I expect a lot from upcoming blocks of Thunder along with AESA & other Chinese EW
BUT does it mean if we get a chance we dont get Turkish EW or upgrade our US weapons n get new one??
Conclusion:
Again i will repeat, if Pakistan can get new Vipers along upgrading old ones, go for it;
DIVERSIFICATION &
INNOVATION is a great thing.