The strongest advantage of Chinese aviation is knock-offs, or more politely, integration. Chinese aircraft designers are willing to adopt the best practices, as well as design paradigms from all over the world, using canard airframes similar to Eurofighters, strakes like on the F-16, as well as American stealth technology. Having more designers allows China to explore more approaches than their foreign rivals; if you look at US aircraft, on the 4th generation, you had the F-14, the F-15, and the F-18, with each having a different, but effective, aerodynamic configuration. On the fifth generation, however, you're looking at pretty much the same thing, the F-22 is a stealthified F-15 with input from the F-16 (LERX). The F-35 is a budget F-22. Lkewise, looking at the Russians, we see the MiG-27 being developed into the Su-27, then into the PAK-FA, showing a single design lineage.
With both the J-31 and the J-20, China has two radically different design paradigms for fifth generation aircraft. One is a sort of merger between the F-35 and F-22, while the other is a stealthified J-10. The former presents a useful development opportunity to explore the use of LEVCONs, if they ever choose to add it, as well as conventional TVC-only supermaneuverability. If SAC were to go under, on the other hand, China would be left with only the J-20 as a lineage. This has more pernicious effects than merely on aircraft development, it also affects military effectiveness. Having two radically dissimilar aircraft means that opposing forces must train against two different aircraft capabilities, as well as configure their forces to fight two different design philosophies. For instance, the J-31 has potential to be much more stealthy than the J-20, due to its lack of canards and smaller size, resulting in better IR stealth.
Optimistically, it could be that if the J-11 line is nixed, the J-31 has been greenlighted. It needs EODAS installed, but otherwise it shows promise as an attritional stealth fighter for the Chinese, like the F-35 is for the Americans.