Please do not delete pages, and then overwrite them with the English source to not have the 'ar' fallback shown. That's just how it is. If the fallback for 'arz' should be changed to another language than 'ar', please discuss that at Support. Meanwhile, the proper solution is to either translate messages, or do nothing at all to make them fall back. Replacing messages only creates confusion and improper overviews of (un)translated messages.
For now I have marked all the messages you have overwritten with the English source text as fuzzy, so they are properly reported as untranlated until they have been translated properly.