@Blackstone
Checked it again it says multiple system of SU-35 including engine has inferior stability compare to J-16. Also SU-35 perform badly on battlefield under information integrated condition thus determined not suit for modern warfare.
Also the rumor mentioned S-400 has been test fired in a northwestern base and the accuracy "didn't met expectation". This plus improved HQ-9 now have 300km range makes PLA think S-400 is "not necessary".
Basically if the rumor is true the whole sino-russia military export saga is busted.