F-18s super hornet are quite good but not as good as Rafales are in every aspect but what tilts in US favor is they have other things like awacs, Satellites, other sensors which sensor fused in single war room which makes them deadly. Similarly su-35 is much better than f-15 but again US wins it war with complete war room assets all sensor fused. You use any of these US teens on standalone basis they will be quite disappointing. That's why IAF is wary of these and had gone for Rafales and su30mkis which are better standalone platforms.
If China can afford SU-35s they can definitely afford J20s which will cost them half of su35s and money will remain in chinese economy. Why they are buying SU-35s is because they know they have a DUD 5th gen fighter which is not having an operational AESA, ew warfare suite, no sensor fusion and shitty engines. Again this flying pig is 5th gen modified copy of mig1.44 which Russia scrapped. J-15 is even worst that MIG29k s as they are unable to lift even what MIG29k can.
WRT TOT, it's not called TOT, it's called theft, daylight robbery, and Chinese are daylight robbers. We can call them monkies too copying everything, these thieves even copied Bajaj Pulsar bikes and Jaguar Q7 SUV owned by Indian companies. That's why now no one is ready to provide them any weapon systems and in fact US companies are considering pulling out of China. Even Russians are not ready to priprov anything to chinese. China wanted s117 engines for j20 but were denied since they knew they will try to copy it. China wanted to buy only a couple of SU-35 s for s117 engines but Russia insisted more and China eventually had to buy 24 SU-35 s and that too with restrictions that if they opened fighter all warranties will be void, same for S-400s china was denied 380kms long range 40N6E which india is getting, in fact India is getting S-450 with a few components from S-500s. So you see copying doesnt help. All chinese J-11,12,13,1415,etc. series fighters suck and fall from the sky due to substandard engines and lack latest warfare elements which su30mkis have. Even rafales are far ahead of J-20s and J-31s. Chinese products and weapons are all smoke no fire....