Hi, It is understood that PAF will not tolerate a gap in already gained strategic elements, however the chances of replacing Mirages with J-10 or SU-35 would PAF not attain much benefit. Mirages are destined to be replaced by 2025-27, by this time F-35 or PAK-FA would be available with India. To counter this threat PAF would ideally be looking for an asymmetrical option. IMO PAF would realistically be looking more towards stealth drones(6Gen) with 36-48 hr endurance using them for strategic role along with stealth(5Gen) air superiority fighter to provide deep penetration. Project AZM was announced almost 2 years back and nothing much is available in public regarding its development till date. We also know that it is really difficult for PAF to fund the JF-17's project which indicates that project AZM would also face shortage of funds indicating this might get delayed.