Yes, Andy. But you want to operate the Z-18s off those 2 vessels as they (should) have better range/payload performance, and are the only combat vessels that the Z-18s can operate off.The Z-20 can also operate from the 055 and the carrier itself, as well as possibly the resupply ship, which I believe covers the entire CSG.
If a CSG has 2 large, and 4 medium destroyers as well as 4 frigates, that’s 12 hangers and 10 decks suitable for Z-20’s.