I'll be honest -- I know very little about the hero's journey. I'm not much of an epic fantasy writer/reader, though I've become more familiar with the classics over the years. And I'm more focused on writing a good story than following a specific formula.
However, there is one step that sorta intrigues me. My take on it may not be exactly accurate, but perhaps it will be refreshing for you to see a different perspective.
I'm talking about "The Belly of the Whale."
Campbell, the Hero's Journey Oracle, defines this step as:
The hero, instead of conquering or conciliating the power of the threshold, is swallowed into the unknown and would appear to have died...Instead of passing outward, beyond the confines of the visible world, the hero goes inward, to be born again. The disappearance corresponds to the passing of a worshipper into a temple—where he is to be quickened by the recollection of who and what he is, namely dust and ashes unless immortal....That is why the approaches and entrances to temples are flanked and defended by colossal gargoyles: dragons, lions, devil-slayers with drawn swords, resentful dwarfs, winged bulls. The devotee at the moment of entry into a temple undergoes a metamorphosis.This particular step is near the beginning of our hero's journey in Campbell's formula, the point where the hero can no longer turn back. According to changingminds.org, entering the Belly is basically the point in which the hero first enters the dangerous lands. Based upon this definition, "The Belly of the Whale" must be toward the beginning of the story.
But the phrasing that is fascinating to me is "the hero goes inward, to be born again" and he "undergoes a metamorphosis." I don't know about you, but to me that sounds like an epiphany moment. And at least in my experience, that rarely happens at the beginning. Even in Harry Potter, this epiphany moment happens almost literal to Campbell's description at the end where Harry "appear[s] to have died," "metamorphos[es]" and is "born again," ultimately defeating Voldemort.
Even the step's title story of Jonah and Whale has the epiphany at the "end" of the story. After Jonah repents from his disobedience of God, he is spit out on the shore by the whale, then preaches repentance and converts the people. But realistically, who remembers the last part of the story? Relatively few. Everyone remembers him being swallowed by the whale as he tries to escape God, repenting, and then the whale spitting him out. The rest of the story is the falling action, which ties up the loose ends, but as far as story is concerned, we don't particularly care.
And so it goes with almost everything we read.
To me, the "Belly of the Whale" is analogous to the climax, the epiphany, or is at least an ongoing thing throughout the whole story. In epic fantasy, the focus is on the external adventure, the journey. But that is not the case for many stories. Many stories are more about the internal and emotional journey. It doesn't happen once at the beginning and then we're done. If that were the case, we'd be bored with these stories because we read many of them to watch the character grow into a better (or sometimes worse) person. This is particularly true in YA and MG.
As I stated at the beginning, however, I may be completely misunderstanding this step in the hero's journey. However, perhaps looking at the overall idea in an unfamiliar way may spark some new ideas in you.
My advice: leave a bit of "belly" for the end.