I agree that the USN rank and file may have had an opinion, but that that was based on their own perception, which at best was lacking direct insight in the man and at worst the opinion of their bunkmates.
A journalist may ask a sailor for his opinion about an Admiral, but that is just what it is, an opinion. It leads to neither wisdom nor insight. Likewise the opinion of junior and intermediate officers, still no wisdow but perhaps a bit more insight. Being an admiral isnt a popularity contest.
The only opinions that matter for admirals is those of there peers, and their political bosses. As a strategist Helfich probably failed in the completion of his task, as a tactician he was untested but he scored high on management, policy, organization, training and motivation, which are the main functions of an admiral, eventhough he was not a bureaucrat.
Politically he became a major factor, especially due to his very close ties with the Royal House. Not well known perhaps, but he was the man behind far east asia intelligence and policy during the '50s, and one of the organizers of the first Bilderberg conference. Not shabby for a little man from Semarang.
In the end he served the interests of his country well, regardless of foreign perceptions. (it is the premise of the rubric that it concerns the Dutch perception).