A person with a conscience would never do such a heinous thing. It is now easy to modify papers and produce two very similar versions. Multiple submission of articles with the same substance is not viewed as an acceptable practice by the economics profession. If they are two different papers in substance, there is no problem. But if the substance is the same, a problem may arise.
Cosmetic changes are irrelevant.
Its size is not known. 4 times 4 is 16. 5 times 5 is 25. You take 16 from 25 and there remains 9. 3 is the breadth. He could still write a paper providing a proof later Euclid found a more elegant proof which is now used in textbooks or stating his discovery of irrational numbers, a corollary of the Theorem for which he sacrificed a hundred bulls to the gods.