In fact, the archipelago is slightly off the normal route, and one can only reach the island by slightly altering direction at sea.
The Spanish Merchant Ship was driven off course by a storm, and it was purely by accident that they discovered the island; otherwise, their leader "Captain Kilian" would have likely chosen another island as the treasure location.
However, that island was different from the archipelago; though completely deserted, even birds didn't poop there, it wasn't far from the route.
If they frequently docked near the island, it would eventually arouse suspicion and lead others to find the treasure, something all sailors wished to avoid.
Because the archipelago is remote, weaponry isn't of pressing importance.
Moreover, there are no large predators on the island; even the birds and beasts that could be hunted for fun are scarce, so the matchlock gun usually hangs on the wall.
