They need some for testing and training. I don't see a lot more than two per carrier. I don't see that plase used a lot from land based airfields with KJ-500 who have probably better range and capabilities... How many KJ-600 do they need ?
I would expect Chinese carriers to be operating to the East of Taiwan, say 1000km from mainland China.
So 4 are probably required for continuous surveillance of the local area.
But I could see them carrying more.
Surveillance is more important that the number of fighters, given:
1. an airwing of 40? aircraft on the carrier
2. the distances to Guam (approx 2000km) or Japan (approx 1000km). That limits the numbers of fighter aircraft in the area