Upon a second listen, this story makes a bit more sense. First, it's apparent that the main character (Soap/Will/Art/Wolverine) is Sociopathic. He thinks nothing of lying to other people, and from the narration of the story, feels very disassociated with everyone. I noticed that through-out the story, there is no talk of motivations of any of the characters. Things just "happen". People just do things, apparently without much logic or reason. Even when it's obvious to the reader, e.g. when Carly all but invites him to bed with her, the main character seems utterly oblivious. "Soap" is the first name that we know him as, a name that denotes cleanliness, forgetting, innocence. Nothing sticks to Soap. Blood and dirt just washes off. Things happen, and Soap just rinses off, and comes out clean, only he's worn a tiny bit smaller.
So, I think "Zombies" represents everyone to the main character. Zombies are the original metaphor for our consumer-focused culture. We stumble around in a society that makes us faceless and meaningless with conformity, mindlessly consuming mass-produced media/food/clothing/cars/furniture/desire that never makes us feel satisfied, all the while stumbling around our daily jobs and roles. So, basically everyone that the main character meets is a Zombie. He wants to fit into society, but he knows that he can't really, and sooner or later we're going to overwhelm him with our sheer numbers, drag him down, and eat him (thereby making him one of us): which is why he's always thinking of contingency plans for escape.
And that's where I run in to the frustration of the unreliable narrator, where because we know the person telling the story is a natural liar, the entire story becomes utterly unreliable. So, basically we don't know anything about what happened.
Overall, I give this story props for subtlety and creativity. It was so surrealistically weird that you can't help but remember it.