Sharlayan: Lore to Map Incongruity?

[Anonymoose]

In the game, Sharlayan is referred to (more than once, in more than one language) as an island city-state within a larger archipelago. However, on the map of Eorzea, it's quite clearly on the main land mass, is it not?

No big lore bombs here, just... what gives?
Did I miss something obvious?

For the sake of completeness, an example:

The city of Sharlayan lies on an island in an archipelago far to the north. It was once a great seat of learning, home to countless scholars versed in the ways of magic.