you seem to be giving J-20C far better capabilities than what it posses. do you think they have superior tech compared to even French?
The J-20C's external capabilities are better, which is why the advantage. If it has an RCS of a sparrow and the engine allows for faster climb, acceleration and supercruise speed than the Rafale, then it doesn't really need to have better avionics than the Rafale F3R.
We can assume that all countries have practically reached the peak of GaAs by now. So a larger 900mm radar in the J-20 will easily outclass the Rafale's 600mm radar. And it can use its passive stealth capabilities to close in without alerting the Rafale. None of Rafale's actual advantages can be put to use until the point a missile is fired towards it. So even if the Rafale's got superior avionics, it may still have to deal with the J-20 having the first look, first shot advantage.
The last time the Rafale received a major hardware update was in 2012-13. The new one will come in by 2024. I won't be surprised if the Chinese are sitting between these two avionics configurations with the J-20B/C.
It has an F-35 style EODAS.
Multiple sensors utilising smart skins.
It's basically like the F-22, but with F-35 style avionics.
Let's also not forget that China's latest BVR missile comes with an AESA seeker and WVR missile comes with an IIR seeker. The most prudent approach would be to assume the J-20C's avionics will at least match the Rafale F3R's avionics. I believe it exceeds it at least in basic characteristics, like larger sensors, more onboard electrical power, more modern design etc.
The main concern for the Rafale F3R is TRAGEDAC (passive tracking), INCAS (datalink) and DEDIRA (AC) are yet to be implemented or not yet implemented fully. And by the time it's implemented and we get the first jet, we may be looking at a whole horde of fully operational J-20Cs across the border.
Furthermore, the Chinese have already started the development of a J-20 successor. They want to make it available around the same time the NGAD becomes operational.