So, the merchant nations are The Empire of Glaewin, the Most Serene Republic of Nuinesia, the Crossroads, and The Despotate of Babel.

Glaewin lives on the plains, and trade primarily on land. Nuinesia dominates sea trade. The Crossroads trade heavily on land, and a bit into the subterranean if I read right. Babel trades mostly at sea, but also on land and into the underdark.

Glaewin is composed mostly of human-like land-dwelling races. They are excellent diplomats, and fair people, but corrupt when it comes to wealth. 

Nuinesia is composed of sea and coastal dwelling races, and a dragon. They are noble, just, honest, and well-respected, but this belies their scheming nature. 

The Crossroads are made of the scheming, under-dwelling races. They're silver tongued tricksters, but many must do business with them anyway out of necessity. 

Babel is composed of desert and coastal peoples. They are the primary traders and raiders of the deserts and south seas. They are praised and damned equally for their lack of loyalty, even to coin.

This is just what I read from the descriptions. Feel free to correct me if I did not remember your nation right. Also, I noticed the guy who made Glaewin hasn't posted in almost a week.