I’ve seen Russian planes on disused ramps and runways that are so overgrown with weeds and crap, that they don’t even bother with “inlet protection”...they make their engines to eat FOD....
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.