I would like to add that the fabled city of Atlantis was an actually place and is believe to have existed on the island of Crete. In RTW that Island is called Kydonia. Their civilization was devastated by a volcanic eruption on a sister island that caused an earthquake and tidal wave that subsequently destroyed much if Atlantis and in particular its trade fleet/navy. With their power base eliminated they were vulnerable to attack from marauders and were eventually destroyed.

The Atlantans were the richest and most powerful civilization of their time. They enjoyed a rich culture and standard of living above all others that would not be seen again for centuries. They even had running water, sewers, and paved streets many centuries before anyone else.

Perhaps you should base the Atlantans on Kydonia? It would seem more realistic and historically accurate. Give them powerful naval units with good speed, attack and defense. Let them produce Cretan Archers and phalanx and nice calvary.