There is nothing 'unconscious' about creating a long epic. It takes conscious effort especially if you expect it to be coherent and enjoyable. Besides, is there a connection between schizophrenia and metered speech? Wouldn't a schizophrenic epic be unmetered?
Tourette's is an example of the barrier between impulse and physical action being weakened.
Schizophrenia can be seen as the weakening of the barrier between impulse and belief.
Telling an epic story off-the-cuff requires weakening the barrier between your subconscious and speech
Personally, I think it's more likely that there was a collection of oral stories passed down by healthy people, each illustrating a specific real-life lesson, that got collected by one guy and stitched together. In the same way modern showrunners borrow scenes and references.
Like Achilles' heel is a warning against pride/arrogance, and the Cyclops and the sheep is a fun way to expose kids to possessive anger
I have a whole gripe with the "unconscious", unless all we mean by it is "past events affect who you are and affect your behavior" in which case I cant imagine Freud is the first person to have believed this.