my comment
One missed on thing about Zeniba. While many consider her good because she welcomes chihero and company, has her guide , lantern, help them through the dark forest about her home. Is hugging and gentle and kind. What is missed to the parallel between Zeniba side Yubaba is the negativities, maybe not evil, in Zeniba. Yubaba lives close to the gates to the living world, so she can actually interact with those who may become lost. Yubaba is like a community organizer of various spirits who have become lost or need a balanced life. Zeniba lives very far so much so even leaving at the early morning by train she can only be reached at night. She doesn't offer any assistance even though she can reach Yubaba's lands as she proved with the paper airplane creatures. Zeniba has never had a child meaning she has never opened herself up to certain kinds of relationship. Zeniba may not have what people can an evil aspect, but she has her own negativity, which i think is missed in ghibli's "good" characters at times.
in amendment
so @Miguelmunuera2601 are you saying the best writing strategy is to do the nippon 4 act in the jeudeo christian three act.