I had the chance to work with Russian aviation and I was impressed with their technology. It was crude but made a lot of sense. Their aircraft does not need all the support as ours.
Those fighters you mentioned can close their main intakes during taxi and suck air thru the aux doors on the top. No FOD ingestion. You won’t dare do that with a F-16.
There is an old Russian saying that goes something like “innovation is the enemy of good enough”
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I’ve been around a lot of Russian stuff too, and I’ve always been impressed with the practicality of their implementations. That said, there is also a lot of truly elegant implementation of common scientifc principle and practicality that I admired.