Atlantis didn't have any edge that's why they lost. BP argued for peace because he didn't want to see anymore Wakandans die in that.
I think Namor made the right decision by blowing up the Great Societies earth but I'm not going to ignore this
You think Namor's claim was just hubris? Or that Wakanda would have won without a sneak attack?
And I fully agree, Namor was in straight "I don't give a fukk mode" right there, but that is what makes him a great KING/RULER and not a HERO. Heroes don't make great kings. T'Challa wasn't willing to do anything he had to do to ensure the safety and survival of his people, Namor was.