How exactly will nato overcome a IADS, RuAF is having a tough time trying to find the hidden S300 radar site and mobile launchers and Buk M1. Nato has to go find the hidden S400 launchers, russian have high powered early warning radar/over the horizon radar, search/tracking radar of S400 and buk m3, Tor, Panstir, Tunguska and a bunch of S125 sites. Also supported by Awacs and R37 equipped Su35 and Mig31, how exactly will those growler type aircraft survive.Honestly, S-400 stands little chance. NATO is flying constant ELINT/SIGINT missions since last year, they know every capability of Russian systems by now. Western EW is miles ahead of what Russia got.
Even the mighty F35 will find trouble finding a hidden Buk m1 to m3. APG82 radar SAR scan can show a vehicle in open grounds but in dense tree cover, it won't know jack shit. The russian mobile radar operators are not dumb enough to give away their position.
Remember the S125 shot two F117 stealth aircraft