Which minor navy had the strongest ASW doctrine?

Which of these navies had the best anti-submarine warfare doctrine?

The Dutch, by a substantial margin, because they worked hardest and had the deepest relevant experience.

The answer is brief and categorical: among the four navies, the Dutch worked hardest at anti-submarine warfare. The wider lecture establishes why that judgment is plausible, because the Netherlands operated the group's largest and most technically varied submarine force. That experience created sustained institutional familiarity with the weapon the navy also had to counter. Doctrine is therefore treated as accumulated organizational effort rather than as a property of one sensor, weapon, or ship.