(Except for Utensia, but I digress)
I recently discovered that an adaptation of L. Frank Baum's Scarecrow of Oz was in the works by the same studio that has previously done a Tin Woodman of Oz film. (I gave it a pretty big thumbs down)
The original story was clever in many ways, mostly by subverting romantic tropes. Although the Tin Woodman and the Tin Soldier are rivals for the affection of Nimmie Amee, neither of them really loves her. You see, now that they're tin, their hearts are not as capable of properly loving her (The Tin Woodman got a heart from the Wizard, but it was a kind heart rather than a loving heart. The Tin Soldier got a tin heart from the tinsmith, but it was cold and hard.). When they finally find her, they discover that she is married to an unusual man named Chopfyt who is actually made of their original meat parts (You know, the bits that got cut off and had to be replaced with tin). So, in a sense, neither of them wound up marrying Nimmie Amee and yet both of them did.
The movie adaptation revises the story so that the love story is played straight. The Tin Soldier is gone, though Nimmie Amee is still married to Chopfyt. But this happens early in the film, rather than at the climax. Instead, the Tin Woodman meets a Tin Girl (who happens to be a tin replica of Nimmee Amee) and falls in love with her over the course of their adventures.
Even though Baum wrote 14 books in the Oz series (and a number of other books as well), he never reverted to formula. Even when he was repeating himself, he never truly repeated himself. For example, Tik-Tok of Oz was an adaptation of his musical extravaganza The Tik-Tok Man of Oz (itself an adaptation of early Oz novel Ozma of Oz) . While each of those stories shared the same basic narrative, the details quickly became radically different.
So when you're preparing for your next Oz adventure, don't worry so much about the "supposed to"s. Baum didn't.