In the WVR combats, but other than that J10A is clearly inferior compared to most Flanker versions. Be it radar range, better speed, can carry more weapons, variety of weapons and longer range in general...
J10A is a 4th gen fighter and will be upgraded to 4.5 gen with the B version and btw, the backbone of an air forces is always the less capable fighter in higher numbers! F16 backbone, F15 high end, J10 backbone, Flanker varients high end, JF 17 backbone, J10B/F16 high end, F35 back bone, F22 high end...
Each fighter is better suited to its weight class(
Hence the MMRCA was the medium multirole combat aircraft)..
Otherwise an upgraded Su-30MKI would do it all for the IAF. Each AF has its own requirements, drawn up by its key decision planners ..in the case of the PAF its the ASR or Air Staff requirement.
Back in the 80's.. the PAF had an ideal ASR for a new fighter it needed, even before the F-16.. but when the F-16 came along, it was so well suited to PAF's ASR that it was nothing short of ideal for it.
Which is why the PAF's love affair with the aircraft has been that long, it was everything the PAF wanted and more.
Today, the JF-17 is one aircraft
designed around an ASR. It meets all the requirements the PAF planners set for an aircraft to fit a particular slot in the PAF warmachine to carry out particular tasks. At the same time, the F-16's in the PAF have particular goals and tasks set out for them(the sq assigned to them having their own war time goals.
The last ASR niche(for a 2018 timeline) was to be fulfilled by the FC-20(
since the other ideals..the Rafale and Eurofighter were either too expensive or came with too many strings attached) ,since whatever requirements were set by the PAF after assessing all future adversaries and threats, and after assessing its own possible financial limitations .
This FC-20 was based on taking the basic J-10 airframe, and along the lines of the F-7PG ..making improvements to suit the PAF.
As time went on, and the JF-17 came up with the DSI intake.. this FC-20 concept mutated into the J-10B with much more improved capabilities thanks to a (in the pipeline) new engine, radar, avionics, ECM, airframe changes etc.
As of now, the FC-20 is still a fluid concept due to funding restrictions.. however.. PAF representatives and engineers at Chengdu and otherwise have access to the J-10B design section..and give their input, their preferences, their ideas to keep refining that concept(
which the Chinese appreciate since it ends up helping them have an improved product for their own use as well)..
Concepts that would include dual rails, further RCS reduction, Improved ECM, Improved man-machine interface..etc.
Now.. such a fighter, improved from the basic J-10B ...may end up being more potent many scenario's of A2A combat than a larger sukhoi due to many factors that effect A2A engagements..from Radar detection range, RCS, Missile range, Energy efficiency.. etc.
BUT, can the same aircraft perform as good as the large sukhoi in many other parameters of range, weapons payload, survivability..etc? NO, each aircraft is designed to match a forte, a niche.. no matter how many permutations of the "role" tag are put in their. A Rafale may be able to engage A2A and A2G targets simultaneously.. but it cannot do so 1500km deep into Enemy territory without compromising on payload, speed and fighting ability...something that the Sukhoi -30 series excels at.