@uniaka:
I don't see why the plan has to fail, unless oda jumps to the fire festival fast(like when he did with the wedding). But so far the days are going slow, 9 more left, barely second act out of 5, maybe because oda wants to show the rêverie final before it ends and gives luffy time to train. Like kaidou pirates could expect the fire festival attack and be prepared but they will still lose in the end, unless fire festival will be like act 3 or 4.
In storytelling, whenever characters have a plan, it can only go one of two ways. it succeeds, or it fails. Now, in order to avoid boring the audience and telling the same event twice, there's really only two ways to show this. (This is especially the case with heist capers where a group needs to commit a crime of some sort.)
1-don't tell the audience what the plan is, so they can see the events unfurl while the plan is in motion. the audience is then surprised and worried and goes along with it. This works if you have a really interesting surprise visual or unique secret twist you don't want to give away.
2-tell the audience exactly how its SUPPOSED to go, and then have things go wrong along the way. the drama then comes from the unexpected twists and changes.
You can also have it somewhere in between, like with the attack Big Mom plan, we knew Bege's plan, and that failed, but we didnt know how exactly Luffy was going to do his specific distraction. Combo.
Either way, you're not giving the audience the same thing twice, and you get the same result either way. The only real question is where you want the drama and suspense to be.
Detective story murder mysteries work in reverse incidentally… it starts out with the crime committed, and then the detective slowly pieces together the clues to tell you how it was done.