Kaido seems rational and intelligent when he is sober, however, there are some of his actions will lead to his own dilemma, here are the few observations:
·Kaido is a beast, but given with his enormous power and strength, he is only one Kibi Dango for O-Tama which unknowingly let her alive and survived.
·Held captive strong pirates or samurais in one place can be a ticking bomb that anytime could explode when someone prison break and free the other captives.
·Putting Eustass Kid in a place sorrounded by a metal (very precious one indeed) is giving him a very dangerous leverage of his Devil Fruit.
·Placing Luffy sorrounded by plenty of food and water is like giving him unlimited Gear 4.
·Making Luffy works hard while at prison cell is like another semi pre-timeskip training.
·He ignored Law get away for a while and instead drink more, that is one of his biggest mistake, Law will be more sharp and strategic from now on, possibly including much effective plan of using his “Personality Transplant Surgery” to explore Kaido’s weaknesses.
·He let the likes of Shutenmaru to roam around Wano, as Shutenmaru says “never underestimate the samurai”, I think there still plenty of strong samurais out there hiding for 20 years, preparing themselves and get even stronger so they could fight back Orochi and Kaido.
*Theory by theorymaru