I was thinking the Overall Story Domain is simply "WestWorld". It's the physical universe, institution, system everything and everyone is contained it.
That would put the Relationship Story (or Stories) as Fixed Attitude. This could run through many of the MC and IC character relationships as a general theme of the Fixed Attitude of Humans vs. Robots much like Humans vs. Slaves.
With that there might be many MC and IC throughlines that all play within and relate through the Fixed Attitude relationship stories.
There's Dolores, who is the first character we see (I believe, if I'm correct). And is the character we often follow from the beginning of her daily routine/default program. So I think she would be a significant MC. But who is her IC? William? Bernard? Teddy? Perhaps the story name is "Dolores's Awakening to Consciousness" or "Dolores's Reverie"
Then there's Maeve, who seems to develop into an MC as the story progresses and her awareness builds. Who is her IC? Bernard? Lutz? Hector? The memory of her daughter? It seems Season 2 will be about finding her daughter. So Season 1 was about the recurring memory of her daughter from a previous life/build is what flickers to create here desire for consciousness. So perhaps its "Maeve's Reverie"
Then there is Dr. Ford and Bernard? What about their stories as colleagues and adversaries?
And William's/The Man in Black's quest to find the center of the Maze. Is that linked to Dolores quest as well? Oy!
I'm stuck here. And I may be in the woods. Is the OS Activity as Khodu says? Everyone's quest for consciousness, power, the center of the maze/solution of the game? Oy vey.
Analyzing a Series with multiple story lines will be a fascinating learning experience. Can an MC be the IC in another MC's story line? I suppose the answer is yes. This is where it will get complicated to analyze. i gather there is an elegance in this structure somehow. And you may have your hand on it Jim because you said the structure is so clear. But I can't see it yet.
This will be fun.