I cannot comment much on the past of Rafael, however won't you agree that mirages were just as capable as F-16's and so a testament to the expertise of the French in producing world class Fighters? With attachment to the French, we could not only have been able to get more Fighters but also would have been able to acquire critical hi-tech avionics and armaments for JF-17's etc.
While I agree that JF-17 would only get better and better and that we will acquire further experience and expertise by pitting Thunders against SU-30's, Rafael's, Typhoon's and perhaps even JSF of friendly countries in the coming years, but what if war breaks out today???
You are giving way too much importance to SAM systems, remember how effective jamming was in Russo-Georgian war? Indian has got way more advanced Jamming assets in her Phalcon AEWACS's etc.
In a war, a real war, no much how much you have in stock, it will run out very very quickly and then you will be without spares whereas IAF will either be producing a lot of her own spares or will still be able to get spares.
Nevertheless, we are where we are and the only thing we can do is to look forward. In this regard, I am of the opinion that PAF skip the 5th Gen entirely, or largely, and start looking to 6th Gen which in my opinion is autonomous fighting machines. Smaller, faster, quicker, artificially intelligent, smart and with next gen weapons. For air-superiority, we must work on autonomous, artificially intelligent systems which are solar powered, able to loiter and perform CAP missions autonomously for days to weeks without the need to land and with next gen directed energy weapons for air-to-air missions. And any country which can establish Air Dominance over her foe, can beat back any enemy.
