Sometimes we’ve written characters that don’t belong in our story because their function is redundant. Conflict might arise that don’t add anything new to the story. In fact, the conflict might distract the reader from what we’re trying to express.
If we find ourselves wondering why a character is in our story, and we’re unclear on what his function is, it’s possible that he doesn’t belong. When we imagine removing him from the story, does it tighten the narrative? Or is it possible that he serves a crucial function, but a function that might work better through another character? We can always conflate characters by distilling one character’s function and giving the necessary traits and situations to another character in the story.