Thank you so much, museful. That is exactly what I was confused about. I asked the question very poorly.
It seemed to me that Dramatica - with its 64 Character Characteristic Elements - sort of "required" a cast of thousands, so to speak.
And if you'd asked me, pre-Dramatica, "How many characters are there in The Omen or The Shining?" - I'd have answered, "Oh, there's so MANY! Tons of them!"
But after studying Dramatica and re-watching some of my old favorites, it gradually dawned on me that there really are very few actual characters in many of these films. It's amazing.
And that's what got me to thinking about how many characters, at a minimum, does a Grand Argument Story actually require. Again, thank you so much, museful.