In the Movies, if Amazons Went To War With The Atlanteans, They Must Be Metas!
Before and after, Atlanteans were already more advanced magically and technologically even before Aquaman came about. There is no way in hell they would have been able to fend off advanced Atlantean technology when they already had difficult with WW2 Nazis.
Yes, they did fight Darkseid's forces earlier on, but then again, the Atlanteans were there, a GL and more importantly, the Gods of Olympus, along with King Atlan.
No Amazon training would have been enough to let them win against a technologically advanced warrior society.