2nd annual offline tournament "Best Of The Best"

The question is more for the map creator, but I would like to know for future reference: it is possible to approach the artifacts between the southern garrisons from the sea, even though the coastline is covered with resources, but landing is possible. Should this be considered a bug or a deliberate design choice by the author? And if it is a map bug, is it permissible to use it if there was no specific warning? Now it is clear that it is not necessary to go there, but purely theoretically...