Do I understand correctly that publishing the same paper in multiple journals is considered self-plagiarism? Who in the name of the great monopoly invented such name for that?
The same morons who think that re-using something you have written before in academic work without quoting yourself is (self-)plagiarism for which you should be sanctioned? (Yes, they are morons because no reasonable person would think this is fair. You need convoluted nonsense arguments to justify this)
Repeating a phrase or two in a document's introduction isn't going to raise flags from any serious people, but copying data, analysis, or large swaths of text? That's a paddlin'.