It's unclear where the J-10C stands today. For one, it needs a significantly reduced RCS compared to the original if it is to gain an advantage over the MKI. If not, it should be able to match the MKI in BVR capability, so it still loses in the numbers game. Plus, it's an export version, so it's not going to be as capable as what the MKI already faces across the Chinese border.
It's a really, really good thing that we are facing two enemies operating pretty much the same technologies.
I doubt the MKI MLU is gonna deliver in just 2-3 years. While R&D work has been going on since quite a long time, we should sign the main contract in 2022. But by the time prototypes are tested and the first set of jets introduced, it's gonna be many years.
In any case, the MKI really only needs a new BVR weapon, and the Derby ER is coming in.