Once familiar with the Dramatica theory of story, many writers wrestle with the RIGHT answer when it comes to choosing a particular Storypoint.
When the Author finds themselves able to persuasively argue a story in either/or, there is no RIGHT answer. The question to really ask isn't whether the OS sounds like it is in
Psychology but rather, What do you want to write about?
Do you want to focus on the backroom scheming amongst all the characters and their manipulations going on in the Overall Story? Or do you want to focus on the activities themselves—the fighting, the punching, the kicking, the thrusts, and parries—the physicality of it all?
The only RIGHT answer is the one that connects with you.
Are you writing a horror story where bloodletting and murders take center stage like Let the Right One In? Or are you writing a horror story more psychological in nature, more terrifying regarding the dysfunction shared among all the characters like Get Out?
The Growth Factor
Barring that you might want to consider the kind of Main Character Growth you want in the Main Character. Is this more of a Coming of Age story where the Main Character grows into her resolve and Starts doing something she’s never done before? Or is this more of a Stop story where the Main Character is holding on to something that she needs to let go of?
Now, granted, if it's a Steadfast story, you’ll see that Growth reflected in her attention paid towards the external. But the question still holds—is she holding out for something to start, someone or something to step up to the plate? Or is she digging in with the hope that something or someone awful will stop?
Assuming the Main Character's personal problems rest in
Universe (typical for most films), the Start story will position the Overall Story in Psychology; the Stop story will shift the Overall Story into Physics.
Again, there is no RIGHT answer, only your WRITE answer.
What do you want to write about?