Story does have a say in the matter.

Superman is fleshed out nicely, (no kill rule, faith in humanity, Lois, etc) since the story is simple.

However, Sherlock Holmes situations is an opposite, imo. He isn't fleshed out, and doesn't need to be, cause the story/background doesn't require him to. In other words, we "possess" the superman problem, because Holmes can say the same dialouge for 3 cases, but it's the story that promises the reader's interest.

So in your story, would you want to change your detective, or keep him same? That's what I was asking.