It is not an insult friend, but in my view, U seem to be somehow naive.
Didn't you realize that the existence of Israel is not only due to the help of Western countries to the Jewish state, but mostly thanks to Russia, and China. I remember during the 90's and 2000's Israelis and US high responsibles rushing to Moscow to implore Russian leaders to not sell not only S-300, Pantsir, Mig-31, and SU-30 to Iran and Syria but they had been imploring Russian leaders to not equip Iran and Syria with just AK's ammunitions because Russia produces some of them able to penetrate any bulletproof, and Hummers. No use to talk you about ammunitions able to down AH-64, and F-16 like SA-14, SA-24, just as the redoubtable SSN-X-26 in order allow US fleets, to swagger along Iranian, and syrian coasts, and to allow US armored divisions to swagger across Iraqi, Lebanon, Palestinian 's streets. Do not forget that Russia, as China agreed, complied.
The deal U hopped is far to be obvious. Such technology's transfer means a political decision and a very hard choice for the Kremlin's leaders. If there were Brejnev, Kossygin, etc...It would not be a problem, but with this actual administration in Moscow, it would be doubtful.
If they go through this deal, what does it means? It means clearly the end of Israel. Neither IDF, nor US can sustain a such challenge. During Vietnam's war US lost more than 4.000 -fixed wings- aircraft, US's economy was at knees US were expelled out of Indochina, US's puppet regime called the government of South Vietnam disappeared and all against VPAF composed by Mig-21, Mig-17 and Mig-19, far to be the state of the art in that time. Moreover in that time, China provided North Vietnam's army, as FNL with bullets able to cripple any armored vehicles and helicopters. Hence US lost several thousands of helicopters.
Imagine the result now if Iran is equipped with these state of the arts Mig-35, SU-35? It does mean Russia and China will give up Israel, and West. In my view, it would be crazy.
I don't say a such deal is impossible, but in my views it would be doubtful. Nevertheless, North Korea can do it but has not yet the technology available at 100%. However, NK is fast progressing they are able to produce indigenous Mig-29 and its jet engines RD-33 around 80%. They are on the verge to succeed, once it will be done, undoubtedly Iran won't need absolutely Chinese or Russians' hardware.