How does the Harrowing Exist?

It seems that the Harrowing mainly happens between Bilgewater and The Shadow isles but if you take a look at locations of these two places you can clearly see that they are in complete opposite spots; -Valoran map-

Now my only explanation to this would be that this is actually the full map of the world which connects from left to right so that would be the only way to possible get Bilgewater closer to the Shadow Isles, otherwise the Black Mist has to travel across the entirety of Runeterra. However this raises a major issue, If the map were to be like this it would mean that Iona is INCREDIBLY close to the Shadow Isles and would suffer dramatically more than Bilgewater

On the other hand, if we take a look at the wiki page for The Harrowing, we can see that we have a more appropriate map of Bilgewater and The Shadow Isles; -Black Mist map-

So this could mean threethings. Least Likely: Ionia has some kind of magical super amazing anti-black-mist shield that protects it from the harrowing More Likely but still pretty unlikely: For some reason the Black Mist only decides to spread to Bilgewater Most Likely: Riot needs to update their fucking game map ;) (no hard feelings)

Side note: they obviously need to update the map because the two maps that are given to us look nothing alike

What do you guys think? Do I have a misconception of some sort? Leave your comments below!

(FYI: I know the map is extremely outdated and really needs to be fixed, this post is more like a complaint to riot than anything because I myself love the league of legends lore and feel like I would really appreciate it if all the puzzle pieces fit together)