I know nothing about how they coded the AI with respect to different ship classes, but most IJN escorts had no surface search radar at all until late in the war (late '44), and it is my understanding their SONAR, at least as it interacted with their poor ASW doctrine, was not all that great (ie: they'd go too fast for it to be useful much of the time).
One thing the IJN did very well was visual sighting, however. They did a lot of training for night operations, so I'd expect IJN escorts (whose primary function was never ASW, but night time torpedo attacks) to be particularly good at visual spotting, particularly awful at radar spotting (since they should have no radar in the first place), and so so at sonar.
tater
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