Multiple elements with same coordinates can exist, yes. It's possible to have two station signs on the same tile, if one of them is a "ghost" station, and the second non-ghost is built holding Ctrl.

I've managed to try it out, and it seems like it works. Now it should handle multiple items with the same coordinates. This version is based on the RemoveRecursive function.

In the meantime I've realized that I don't need this function where I wanted to use it, but I think it good to have an element checker none the less.

Not sure I like PRs that add code but don't use it. What's the usecase for this?

Well, after realizing that I don't need this modification for my other PR (local town authority displaying), I cannot think of another useful usecase. That being said, I am not against closing this PR.