As I said, the concept is different for swords, can a sword do internal damage without cutting?
Use the same Ryou from ODEN with a sword and not with a punch, but ... So, whatever ACOA the sheaths are using, ZORO also has it, because he cut KAIDO, as you suggested, it could be another variation of ACOA for swordsmen, and I agree with you, but it will always be stage 2, as we saw the basic COA of luffy after WCI, failing at KAIDO.