Halsey in search of self glory was lured away from the landings at Leyte Gulf by Admiral Qzawa, but indecision and poor decisions by Vice-Admiral Kurita and American air superiority avoided a major US defeat.
MacArthur was another glory seeker in WW2, and had severe mental problems by the time of the Korean campaign, blaming everyone else for the problems. He wanted to use the atomic bomb against China, Truemans intervention by dismissing him just in time barely avoided a nuclear wasteland and possible further escalation.
Nimitz is the obvious answer, but he had luck and intelligence on his side at Midway.