AFAIK there ARE no Cruiser task groups. TGs are tied to the carriers, so whenever there's a CA group in any event I've flown in the CM has had to manually sink the CV and tweak the respawn timers to make it work.
It was possible to alter the ship number ( so that the cruiser become 001) in the terrain editor when deleting the cv. An invisible tower/OC and hanger point object had to be constructed to give the player a view point. ( usually to the side of the cruiser). Only ships guns were available ( set in arena settings) or maybe the odd PT or LVT.
Then a CV free battle fleet could be created. Several Scenario terrains had this. ( early BoB, Niemen )
Indeed some MA terrains had two cruisers per CV fleet and at least one scenario terrain had fleets with multiple CV's all using the same tools.
HTC discourages the use of " modified" object groups these days.