When I first started using the translator, I was aware that I couldn't publish an article with a name that clashed with an existing article. I could publish in my own namespace and then copy across, so that was fine. Last year I became aware of a few users on cy.wikipedia.org that published the same page multiple times from the translator (after making different changes). They would publish a new article, other users would come along and fix things, then the original user would publish again (with their own changes) overwriting the existing article.
So it seems that the translator tool is not warning of existing articles any more?
I have seen the issue myself this week. I prepared a translation of an article that didn't exist, which took an hour. I published it but then discovered that another user had already created the same page a few minutes before (not using the translator, they had just created a stub).
I also created an article a few weeks ago using the translator and them someone else a few hours later published their own version also from the translator, as they probably had it in progress.
Is there a way to once again warn users if they're about to overwrite an existing article? and maybe offer to save in their own namespace?