Albatrosses & Mollymawks

The smaller albatrosses may be called either Mollymawk or Albatross, so I have ordered the images alphabetically, ignoring this part of the name. So Mollymawk, Buller's comes before Albatross, Northern Royal, which in turn comes before Mollymawk, Salvin's etc. Hopefully this will make navigation through the different species more simple... To complicate matters further, as yet there is no definitive classification of the larger, Great Albatrosses into individual species or subspecies. All are included in the genus Diomedea, and some (the Northern Royal and the Southern Royal) are sufficiently distinct to have long been recognised and recognisable as individual species. The remainder form a species complex which, for simplification, I am going to call Wandering Albatross (Diomedea exulans), but which includes forms that may eventually be classified definitively as either species or subspecies: Antipodean Albatross (Diomedea antipodensis or Diomedea antipodensis antipodensis), Gibson's Albatross (D. gibsoni or D. antipodensis gibsoni), Snowy or Wandering Albatross (D. exulans) and Tristan Albatross (D. dabbenena), this last not in NZ waters. So in theory what I am calling Wandering Albatrosses should be divisible into Snowy, Antipodean and Gibson's Albatrosses, but to confuse things further there is a large degree of plumage variation with age. If the experts cannot agree on a definitive classification, what hope do I have?