But there are many articles written as if Holmes is a real person, such that we could extract valuable life lessons by studying how Holmes solved problems - on the implicit basis that it worked out well for Holmes.
That a particular way of thinking worked for Holmes doesn't mean anything. At best, you are hoping that Arthur Conan Doyle had a particularly good model of the world, as reflected in his fiction, that is worth studying.
Finally, the advice in that particular article seems contradictory, to me. E.g:
“I make it a practice not to judge someone before I speak with them and get to know them. But can I tell you who someone is by looking at cuff links? No.”
Which is the article saying we are supposed to do? Wait for someone to speak before judging them? Or make educated guesses, based on prior knowledge of the world, and observations such as the cuff links they wear?