With the proliferation of the J10C model, which should be far better at air to air than the J10A, are the J10A brigades focusing more on air to ground and/or CAS missions?
Zero indication of that and it doesn’t make sense. The PLAAF have JH7s, Su30MKKs, J16s and UCAVs for ground attack on top of H6s and land based missiles/MLRS and naval options. J10As lugging LGBs doesn’t really add much value for ground attack.
While individually, J10Cs are far superior to J10As in just about every field, much of those advantages are reduced in the context of realistic large scale air combat. Since you would reply heavily on AWACS and data links in real world combat, meaning better individual fighter radars and IRSTs will not be such a huge deal.
I expect the J10As and J10Cs to instead focus on aspects of air combat that maximises their respective strengths. With J10Cs loading up on PL15s to do long range alpha strikes, which will also aid the J10As in getting closer to those their PL12s before all piling in to finish what is left with PL8s and PL10s.
When used like this, 10 J10As and 10 J10Cs should perform almost as good as 20 J10Cs.