The first one, the original-era Su-37, looks almost like a "Rafale-ski" from the top, while the S-56 looks almost like a twin-tail "Falkonski", or perhaps some F-16 got frisky with an Su-27 in the back of the hangar.
I like all these old cancelled projects that people manage to dig up. They are quite fascinating, especially that S-37 thing. It would have been interesting to see something quasi-resembling Western strike fighter designs enter Russian service. Going by the bulky, well-built nature of the models and the mass of hardpoints, I'm guessing this would have more followed some kind of Strike Eagle-type analog?
Yes, yes, yes!
I don't know why but the F-22 drawing kind of reminds me of a Tarantula Hawk wasp, probably because of the dark, subdued finish and canopy giving it the look of a flat black, washed-out shell, and just how sinister that plane looks. Nice job!