Any F-16s they might get over the next five years are going to have avionics vastly inferrior to the Russian Su-35's IRBIS-E phased array radar.
If a Ukraine-piloted F-16 fighter group is ever deployed (I have my doubts that will actually come to pass), they better hope to not run into any Russian Su-35s. They will be down before they're even aware the Russians are in the air.
