It's not as worrying as it first seems. asurface actions between Destroyers or Frigates isn't very likely, the air and submarine threat is the main concern.
Surface to Surface missiles are not the best weapon for attacking another ship these days. Harpoons wouldn't stand a much of a chance against modern countermeasures, same for most surface to surface missiles., Torpedoes are the best weapon for surface targets at long range or air launch missiles.
I predict the Harpoons will continue in service until the replacement comes on line and the main SS weapon will be the torpedo.