How realistic is a Halland-style destroyer armed with twin 152 mm guns?
Short answerIt is plausible because Scandinavian yards, especially Sweden's, could build large and powerfully armed destroyers.
NotesThe design enlarges the gun calibre of a powerful Scandinavian destroyer rather than inventing an entirely alien type. Sweden in particular built large, heavily armed destroyers and had the industrial skill to integrate substantial naval guns. The result would sit near the destroyer-cruiser boundary discussed elsewhere in the stream. The design was quite possible, even if it would be an exceptional member of the destroyer family.