A "*_h.blp" is indeed a heightbased texture, it's for the heightbased texturing implemented in Mists of Pandaria and doesn't have any use for us on WotLK or Cataclysm at the moment. And it won't have any use for us on Mists of Pandaria since Noggit doesn't support the heightbased texturing.
Old textures from classic miss the_s texture. But in the template adts the feature is turned on. So you have to createthis second texture for every green one.