Per our Help Center, "the goal of the site is to help you build your world, not to tell your story." Worldbuilding (on-topic) is about the rules and systems of a "world" (no matter its size, community or universe) wherein many stories can be told.
"Storybuilding" (off-topic) is about circumstances, actions, or plot. The moment you start asking about the actions of a character, you're storybuilding. It's theoretically possible that a question about an individual character is actually a question about the consistent application of world rules, but it's very rare (and the linked question most certainly did not meet that requirement).
The more people who are involved in the question, the more likely the question is about the consistent use of a world rule. For example, a question about how an army would counter a technology built upon a rule unique to the OP's world would be on-topic. Theoretically, a question about how a single spy would do so would also be on topic. But, even the population of a nation, if you ask (e.g.) "how can they increase their nation's GDP?" would be off-topic as Too Story-Based.
As a rule of thumb, the moment you ask about what a character should do or how a character can accomplish a goal, you're storybuilding and off-topic.
TL;DR
The question was migrated because it did not meet the expectations and requirements of this site and was judged to be more suitable on another.