There's a huge misconception going on when it comes to determining a character's ACoC haki strength level.
Some fans believe character's ACoC haki levels are determined by how well they can use CoC knock out power, how long they have had CoC or some other way related to whether they specialize in CoC haki. That is wrong. Yamato had ACoC longer than Luffy but her's is not stronger than Luffy's. Luffy didn't obtain ACoC by being good at knocking out characters with CoC. He obtained it by remember how to flow CoA haki.
A character's ACoC haki strenght is determined by how strong a user is without ACoC. Not with ACOC.
The manga tells us you can't train CoC haki to grow stronger. Though you can train to become better at using or controlling it. CoC can only grow stronger by the user growing stronger.
That explain to us why Luffy went from getting his ass kicked by Kaido to clashing evenly against Kaido and fighting on his level just by obtaining ACoC.
That explains why all top tier ACoC users have other powers, abilities, or fighting skills. Garp has his strong fist and physical strength. Roger, Mihawk and Shanks have their sword skill. Kaido and Big Mom have their DF. They need the additional power, ability, or fighting skill for their CoC to grow stronger.
That explains why Oda has Zoro using 2 swords the majority of the time against awakening Lucci and why Luffy has only used ACoC one time against the Kizaru/Saturn. Oda wants us to understand how strong they are without ACoC so we will have a better idea of their strength with that power.
Since rooftop Zoro was stronger than rooftop Luffy and could best hybrid Kaido that means Zoro, Luffy and Kaido's ACoC haki strength are all equal or near equal.
On the side note, this explains why Oda had the marine say Mihawk has greater sword skill than Shanks. How strong Shanks ACoC is, is based on his sword skill strength without ACoC.
Some fans believe character's ACoC haki levels are determined by how well they can use CoC knock out power, how long they have had CoC or some other way related to whether they specialize in CoC haki. That is wrong. Yamato had ACoC longer than Luffy but her's is not stronger than Luffy's. Luffy didn't obtain ACoC by being good at knocking out characters with CoC. He obtained it by remember how to flow CoA haki.
A character's ACoC haki strenght is determined by how strong a user is without ACoC. Not with ACOC.
The manga tells us you can't train CoC haki to grow stronger. Though you can train to become better at using or controlling it. CoC can only grow stronger by the user growing stronger.
That explain to us why Luffy went from getting his ass kicked by Kaido to clashing evenly against Kaido and fighting on his level just by obtaining ACoC.
That explains why all top tier ACoC users have other powers, abilities, or fighting skills. Garp has his strong fist and physical strength. Roger, Mihawk and Shanks have their sword skill. Kaido and Big Mom have their DF. They need the additional power, ability, or fighting skill for their CoC to grow stronger.
That explains why Oda has Zoro using 2 swords the majority of the time against awakening Lucci and why Luffy has only used ACoC one time against the Kizaru/Saturn. Oda wants us to understand how strong they are without ACoC so we will have a better idea of their strength with that power.
Since rooftop Zoro was stronger than rooftop Luffy and could best hybrid Kaido that means Zoro, Luffy and Kaido's ACoC haki strength are all equal or near equal.
On the side note, this explains why Oda had the marine say Mihawk has greater sword skill than Shanks. How strong Shanks ACoC is, is based on his sword skill strength without ACoC.