Problem with the J-10 seems to be related with engine issues & upgradation process, which were the main cause for delays. J-10B production started in July 2013 and J-10C production started in 2015. Similarly Jf-17 block-II & block-III will have the engine issues due to delays in RD-93MA & WS-13 or WS-17. Also new WZ-16 turboshaft engine (~1,500kw) for WZ-10 helicopter will take some time and hence will result late deliveries. Please note that High thrust-to-weight is essential to super-maneuvering fighters because it not only avoids many situations in which an aircraft can stall (such as during vertical climbing maneuvers), but when the aircraft does stall, the high thrust-to-weight ratio allows the pilot to sharply increase forward speed even as the aircraft pitches nose-down; this reduces the angle the nose must pitch down in order to meet the velocity vector, thus recovering more quickly from the stall. This allows stalls to be controlled; the pilot will intentionally stall the aircraft with a hard maneuver, then recover quickly with the high engine power.
Regarding the performance of J-10 against F-16 C/D, yes J-10A (with 123kN engine, without AESA, without DSI) would be inferior in performance but J-10C is quiet different aircraft with maximum thrust of 30,800lb (137kN), AESA radar, semi stealth capability, IRST, DSI input, upgraded avionics & upgraded electronic warfare system. Now J-10C is ready and its performance can be checked against F-16 block-52.