[SunkenCiv]

The observation about the -nth place names isn't from Herodotus, it's modern. -nth place names are found as far afield as the north end of the Adriatic and the shores of the Tyrrhenian. As you said, the H-man grew up in a Carian city, probably spoke Carian or some Carian, probably had Carian relatives -- and of course, was a couple thousand years closer to the problem than we are..

[Verginius Rufus]

There is Saguntum in Spain (the city sacked by Hannibal which led to the Roman declaration of war against Carthage in 218 B.C.), but I don't know if it has any connection with the -nth- or -nd- names found further east.

In the Adriatic the island of Issa was colonized by the Greeks (modern Vis). Two important naval battles took place near that island in the 19th century.