China will need a minimum of 6 carriers, which should ensure that at least 2 carriers are readily available in case of sudden developments/emergencies.
The number could then be surged to 3-4 carriers once the 1-2 carriers that are on working-up are made ready.
With 2 carriers that are on-station at any time, that means either the 2 carriers can work together as a dual-carrier CBG, or each of the two carriers can form their own CBGs to deal with situations that are separated across vast distances (Diaoyu Islands and SCS at once, for instance).
On the other hand, 9 carriers should be the maximum. Any more and the PLAN risks stepping into the shadows of the USN.
6 Carriers yes and I would say
CV-16 and CV-17 thats 2 x STOBAR with 24 x aircraft each = 48 units
CV-18 and CV-19 CATOBAR with 36 aircraft each = 72 units
CVN-20 and CVN-21 with 48 aircraft each = 96 units
Total Naval fighters 216 available for air operations over area far from home
I think that would be a good Navy