So who wrote William Shakespeare's Henry VI, Parts 1, 2 and 3?
Trick question. Unless you are a professional Shakespeare scholar producing the latest Oxford University Press edition of Ol' Bill's plays, in which case you will claim that Christopher Marlowe was the co-author. Why?
Well, as Nick Hilton writes at The Spectator, you can gin up some interest in your new edition by doing stuff like that, as well as by including the questionably-authored Arden of Faversham as definitively being by Shakespeare. And since you're making the claim about three of the Bard's lesser plays, people are less likely to laugh at you for claiming the co-authorship. Not because there's any greater chance he co-wrote them, but just because those plays usually don't get much attention and so no one will remember to laugh at you.
The fact that you have some pretty weak reeds to lean on in doing either of those things doesn't necessarily deter you. Because just making the claim can get you written about, maybe even outside of academic journals! As our two major party presidential candidates have pointed out, even bad publicity is still publicity. We may curse every time we hear either name, but that's still a response. And for certain kinds of malignantly narcissistic greedy grasping septuagenarian charlatans, the response is what matters.
It's still kind of sad to see someplace like Oxford University Press adopt that way of thinking, though.