Su-35 and Su-30 not that much of a difference really, especially in close combat.
It is understandable how the J-10 can have a few advantages.
Canards do have an advantage in close in fights, but the result does not change with the Su-35 which has canards on its own, as you can see against the Rafale and Typhoon.
Size does matter a lot, in close combat, he who sees the other first has won half the battle. Big planes are clearly in a disadvantage against small planes. Dark grey paint job on PLAAF Flankers don't help a bit, while light blue grey on the J-10s are almost perfect against the sky.
Slotted array radar on J-10s may have superior aperture (azimuth and elevation) against the radars on the Flankers. I'm not talking about the range, but the field of view, which is extremely important in close range fighting. Mechanically scanning slotted array radars are very difficult to beat when it comes to FOV, even against PESAs and AESAs. These radars can nearly gimbal for ninety degrees.
Quality of RWR. There is some that say the J-10's is better but the degree of better I don't believe to be that far. The Pastel RWR on the MKKs are pretty good, and the Beryoza RWR on the Su-27SKs/J-11s is still more than good enough to deal with any modern radar except for those with LPI.
At 31 degrees instantaneous turn rate, that certainly exceeds the Su-27 at 28 degrees and the MiG-29 at 26 degrees. That's right up there with the Typhoon, Gripen and Rafale, all canarded planes. The 300 degrees roll rate per second is right there with the F-16 and the MiG-21, the two fastest rolling aircraft you see today. I expect the J-10 to roll faster than a Flanker, by the virtue that a single engined fighter will roll faster than a fighter with seperated twin engines. This has to do with the concentration of spinning mass in the plane's bore line.
I don't believe missiles play any part in this, as the wargames may be radar locking or gun/missile camera contests. I'm surprised that IRST and HMS dont play much of a factor in this; many of the J-10 pilots are not flying with HMS, though a J-10 test pilot has been shown to have HMS attachments on his helmet.
J-10 pilots may be highly experienced Flanker pilots by themselves. They would know all the ins and outs of their former steeds. Those flying the Flankers are already in an informational disadvantage. The ones on the 44th Division may have come from a J-7 background, but the J-10 pilots on the 3rd Division may have been those that once flew the MKKs which are still assigned in that division.