They used haki the way swordsmen use it, as explained before, skills swordsmen are known for their cutting abilities with the katana. Swordsmen have their own 'advanced haki'
Haki is whatever anyone can use
Being a swordman doesn't change haki.
Oda wouldn't waste chapters hyping AdCoA that Rayleigh has just for retainers to showcase before Luffy gets to use it on Kaido and BM.
Did Oden have Adcoa? No
But I believe the had flow/barrier like Roger and Whitebeard had.
When it comes to barrier/flow, Oden had higher level of it.
Oda is keeping adcoa and FS rare that only a few have.
While barrier/flow is something even low tiers can master and use.