Well, yeah the PLA has a quite a number of Flankers in service and are continuing to procure J-16s and will likely continue to do so until the mid 2020s.Contrary to some people I think it is highly likely that China will purchase the Su-57 (likely once second stage version is available in 2022).
These would be purchased in small amounts similar to Su-35 purchase.
I think it is highly likely that China will manufacture J-20s on the higher numbers. Just look the number of J-11 and J-16 fighters.
If you're using using the scale of their Flanker procurement to infer what their J-20 procurement might look like I think you've just demonstrated the opposite of what you were suggesting.