Why Dönitz and the US Pacific submarine war differ

Can Dönitz be compared directly with the US submarine leadership in the Pacific?

Not cleanly. Their command roles, strategic settings, geography, and opposing anti-submarine systems were materially different.

Dönitz should not be compared too directly with the United States submarine leadership in the Pacific. Their strategic problems and command roles were not the same, particularly when evaluating Dönitz as head of the German navy rather than only as a submarine commander. The Allied anti-submarine system in the Atlantic was also a more developed opponent than the system American boats initially faced from Japan. Japanese planners understood that submarine warfare was possible but were slow to prepare for it being used against their own shipping. Similarities in unrestricted operations therefore do not erase differences in geography, opposition, and institutional responsibility.