Were the J-, K-, and N-class ships fleet destroyers?

Should the Royal Navy's J-, K-, and N-class ships be treated as fleet or utility destroyers?

They count as fleet destroyers within the simplified utility, fleet, and war-emergency framework, although the categories require some adaptation.

The answer uses an analytical category rather than claiming that every contemporary label was fixed. J-, K-, and N-class ships followed the Royal Navy's return to larger destroyers after the Tribal experiment showed that early treaty utility designs lacked enough late-1930s capability. Their speed, armament, and intended place with the battle fleet put them on the fleet-destroyer side of the comparison. The caveat matters because destroyer roles overlapped and changed as air defense, escort, and torpedo requirements grew.