WB still had the physical strength, Fruit, all marco said is he lacks CoO is what marco said, literally kaido CoO sucks
The marines weren't worried about kaido, sengoku said he underestimated him
He couldn't use CoO and CoC as he could before. That's confirmed. Why would CoA would be any different than other 2 types? That wouldn't make any sense.
As for physically, he was bleeding and sweating constantly, and he got heart attack during the fight, that also weakens him physically not only in terms of Haki. If your physical and Haki stats are weaker, your capacity of using the DF gets weaker as well, that's how its been so far.
As I said MF Whitebeard wasn't on Yonko level. He was so weak that Marco and Jozu needed to save him several times. It should've been the opposite, Whitebeard should've saved Marco and Jozu. Look at Doflamingo, he saved Trebol from Law after Law used Radio Knife on Trebol, even though Doflamingo was also fighting with Luffy.