Yes I agree. All the moreso because the word fish is very ancient and was used to mean any aquatic animal long before Linnaeus came along and decided to "well ackshully" the word.

This is a reach, but do you know where to find the essay I read about someone explaining to King David that a whale isn't a fish and the King laughs at him because his modern mammal explanations are useless and impractical compared to the ones he uses?

I've been trying to re-find it for ages.