“After gory and costly battles in places like Guadalcanal and Tarawa, he discovered the magic of bypassing islands and leaving enemy strongholds to die on the vine.”
Guadalcanal & Tarawa were Navy/Marine Corps operations, not under the command of MacArthur. I’m sure he noticed those mistakes, but they weren’t his.
The “Dugout” tag comes from his departure from Corregidor — which was ordered.
Probably his biggest mistake was abandoning the planned defense of Bataan & Manila Bay by initially opposing the Japanese landings in Northern Luzon. That cost him men & materiel when he should have been husbanding his resources. Given the Navy’s predicament after Pearl Harbor, relief wasn’t coming, so it probably made little difference.
MacArthur probably made a few mistakes in the early operations on New Guinea, but he learned very quickly from those.
All-in-all, a very capable theater commander.
Try finding a reference to that monniker in any newspaper prior to rumors of MacArthur eying the Whitehouse in '44.
Wouldn't have mattered not one bit.
The actual strategy of defending the beaches was a good one and had the green Filipino troops of Dec '41 not lost their nerve, the Japanese invasion probably would have been repulsed on the beaches. The same Filipino troops that lost their nerve on the beaches began badly mauling the Japanese one month later on Bataan.
While the Guadalcanal campaign saw the vast majority of the heavy lifting done by the Marines, Army troops took part in the battles for Henderson Field, Point Cruz, Koli Point and other locations. Calling the operation completely a Navy/Marine operation isn't entirely accurate. That isn't to understate the valor and sacrifice of the Marines, of course.