When you write a story, a plot may dictate a character… but then the same becomes true the other way around.
I have created many characters who were intended to play a role in a certain novel, only to then realize that they did not have the right chemistry, and ultimately replaced them with another character until the original could play a more suitable role elsewhere.
And depending on which storyline you place a certain character n, their dialogue may or may not be suitable for a certain theme.
For example, I had written short stories and screenplays for the main characters from my novel titled Red Dragons going back to 2008 (or earlier) that took place on the Eastern Front during the Second World War.
Later on, I decided I preferred to make their story more fantasy-based, and so I was able to take far more liberties in their social immaturity than I otherwise would have been able to when they had been cast in a historically-based series.
Similarly, another character in a separate series by the name of Dana Thompson was originally the main character in a horror-based series that I have been compiling.
Unlike her current personality, she began as a very quiet and reserved individual who rarely spoke unless spoken to first.
Several years ago I found the means of making her far wittier than she originally was, and so I moved her into a separate series known as Toon Rangers before replacing her previous role with another fictional character.
Placing an appropriate character in the right role has been very helpful in creating dialogue that flows off my keyboard, because their words end up feeling more natural for the plot that they are in.
Since an author who really wants to make their story stand out is not going to get their pacing, theme, character development, plot, and dialogue right on their first attempt, this would mean that revising — not mere editing — will become inevitable.
Not counting the times when Red Dragons was being written as a historical series with fictional characters, the main novel of the current storyline was rewritten three times from scratch, and in between each of these revisions, I would go through several rounds of editing in hopes of justifying the plot and characters.
Only after my third rewrite did I become satisfied enough that I was able to focus solely on the editing process.
As one can see, it is not possible to complement one aspect of writing without doing the same for the others.
Without revising a story, editing becomes impossible.
Without editing, the plot becomes unworkable.
Without plot, pacing becomes mismatched.
Without pacing, characters have no development.
Without development, there is no functioning dialogue.
Without dialogue, there is no recognisable theme.
In conclusion, one part of storytelling cannot be easier or more difficult than the other, because much of the writing process’s fluidity is reliant on knowing how to balance all six of the above elements accordingly.