Go through the list of F-15 operators. It's not just large countries that use them as their premier air superiority/strike fighter. Even countries with tiny airspace, like Israel and Japan and S Korea and Saudi Arabia field these mammoth F-15s, which often fly top cover for F-16s or their equivalents. The fact of the matter is that despite the larger RCS, heavy, twin engined aircrafts with excellent aerodynamics and powerful avionics and radars make much better air superiority machines. There is so much that an MKI or F-15 can do that an F-16 or mirage-2000 simply cannot. That is why despite being much higher priced, all countries that can afford them will have them in small numbers, in addition to the lower end fleet of F-16 class aircrafts.
So the trollish poster who kept saying that MKI is inferior because of a larger RCS simply has no clue what he is talking about. RCS is not the be all and end all of aerial warfare. Heavier aircrafts can house much more powerful jammers, much more powerful radars, have much more agility or maneuverability, carry many more missiles (BVR and WVR), carry much heavier loads for ground attack, and so on. Each MKI due to their immensely powerful radar can act as mini AEWAC or command post, and guide other MKIs or smaller fighters flying radar silent. In such a case, only the radar emitting MKI will be detected by the enemy, while the shooters would be other aircrafts using that MKI's targetting data through a datalink. That's just one possibility that makes RCS comparisons irrelevant; there are many more.
Pakistanis claiming that a well trained F-16 pilot will stand a better chance simply because an MKI has a large RCS, is simply wishful thinking or denial of reality or both. An equally well trained pilot in an MKI will most probably have the last laugh. Anyway it doesn't mean that an F-16 can never shoot down an MKI, it just means that the odds are heavily in favour of the MKI. Not to mention the other benefits that MKIs have in aerial warfare, like range and load and loiter time.