So God King shanks still clears
Him and Mihawk completely fodderise Kaido
The fact that Zoro can scar Kaido on the rooftop, should tell you enough, considering the power ups Zoro is going to get
You have to now consider the hypothetical of how much damage he would do to Kaido with each consecutive power up, knowing he is still weaker than Mihawk and Shanks.
There is a reason why Oda would never had allowed Kaido to interact with Mihawk, despite Kaido wanting to die so bad. All he had to do was pay a visit to Mihawk.