Anyone who knows the history of the pacific campaign knows that both Yamamoto and Nimitz were directly following long established, indeed published, doctrine of their respective countries.
Neither demonstrated any significant deviation. They both certainly were organizationally competent.
Also Yamamoto was simply put a war criminal. Among the orders that he passed were the execution by Japanese naval personnel of tens of thousands of Chinese POW, the defined and explicit war crime of intentional placement of US POWs on Japanese cargo and troop transports and barges to have them function as human shields, which resulted in the death of over 8,000 US POWs. he even approved of the war crime of executing captured Doolittle raiders.