I would say putting in some mechanical that was considered during design is much easier than reverse engineering it from a narrative!
Not sure I follow. When I prep game sessions I'm thinking about the story I want to tell, what environment makes sense for the story and then populate it with level appropriate monsters or NPCs. I may think about specific encounters and add in traps and environmental hazards as appropriate along with notes about the motivations and desires of my NPCs and the groups they belong to.
What I'm not doing is calculating out specifically who will do what or mechanical details on how I'm going to respond outside of something like "archers in the back while the grunts rush forward". There are simply too many alternatives to what my players could do, and I know the capabilities of my group. I don't assume a railroad, I don't assume they'll do A then B. I certainly don't plan out how the bugbears will respond if the group decided to negotiate with the goblins instead of killing them for example.
Which is similar to what I see in most mods. So again, outside of general suggestions I'm not sure what you could add.