I'm completely fine with Kaido's portrayal; he was a crazy, suicidal, war mongering drunk who wanted to die in battle, so he let his enemies get easy hits on him to gauge their strength, and give them a chance to prove they actually had a chance to kill them in battle, and refused to kill enemies who had damaged him, in hopes the could come back stronger to challenge him later.
It's Big Mom, Blackbeard, and Luffy who have portrayal problems.
Shanks is obviously on another level since he leveled Kid in one hit when Big Mom fucked up and left Kid and Law beat her after leaving them for dead rather than just killing them while they were down. Big Mom and Kaido were clashing evenly for what, two days? So, Shanks is still strong as fuck.
But, it's all about Buggy, BABY, GO BUGGY, BUGGY'S GONNA BE PIRATE KING!