I totally agree with your assessment of the J20 being a sniper. The USAF only major weakness is the major reliance on support aircraft. The J20s mere presence can change the battle for China and they don’t have to destroy any planes to do it. They would force them to operate further from the South China Sea (for example) and limit American intelligence gathering.

The Americans do seem to be adapting pretty fast though. The sensor fusion in the F35 and F22 make a AWACS more dispensable. The development (hopefully) of the Navies first stealth drone into a ISR/Tanker platform extends stealth capabilities to the entire strike package. Then add to this the U2s, Globalhawks, and probably other drones with SLAR and the entire support flight is stealthy or can operate effectively a greater ranges. The result would be one hell of a fight, BUT that’s before allied nations are factored in. The U.K. or NATO as a whole tilts the balance solidly to American advantage in any protracted war.