Although cumbersome external fuel tanks sap the J-20's low observable (stealth) qualities and maneuvering performance, it is likely that they can be jettisoned along with their pylons in a similar manner as the F-22. This allows the aircraft to recapture a large degree of its low observability, and is clearly useful if increased kinematic performance is needed. The tanks will also allow J-20s to reach stations hundreds of miles beyond what they are capable on external fuel alone. They will make the J-20 more independent of aerial tankers for certain missions, and even with four tanks, the J-20's baseline internal weapon carriage capability is not disturbed.
The J-20, or a least some of them will carry weapons under their wings. China's new very long-range air-to-air missile.
J-20s could work cooperatively. For instance, a devision (flight of four) J-20s could work in two sections, one section of two jets in stealth configuration, and the other two carrying four long-range air-to-air missiles. The stealthy pair can venture forward to quietly (electronic emissions silent) obtain targeting information while the J-20s carrying the long-range missiles can act as weapons magazines, leveraging the targeting data obtained from their stealthy wingmen. These are similar to tactics being developed by the USAF for the F-15 and F-22 air dominance team. For instance, the stealthy J-20s can use their passive sensors (electronic support measures and infrared search and track) to silently stalk targets far in front of the non-stealthy configured J-20s. Meanwhile the other non-stealthy J-20s operating many dozens of miles to the rear can use their radars freely, providing enhanced situational awareness to the stealthy J-20s ahead by sharing their radar "picture" via data-link. In doing so these non-stealthy configured J-20s also act as bait, drawing in enemy fighter aircraft, and leaving them vulnerable to ambush by their stealthy and silent counterparts.