Peace time patrols involve a lot cat and mouse chasing games, most times you want to carry just enough weapons to show you're serious at the same time not to compromise your maneuverability.why PLAAF does not like to load up their weapons for their fighters? One PL12 and one PL10, really? Didn't they claim to train the same way as they will fight?
This is common practice around the East China Sea and the South China Sea. When US navy CSG detected PLAAF Su-35s incoming, F/A-18s were sent airborne with no fuel tank and only one 9x to make the upcoming dog fights more favourable to them.