This is usually subconscious and relies on word sounds.
For example, if you want to associate a character with energy and activity, you’d want to use a firm and short name.
If you’re writing a superhero story, you may be able to get away with a wacky name like Captain Carnage or Devil Dog, like Superhero Nation does.Typically, protagonists are active go-getters– otherwise the story would be pretty boring, right? When you name main characters, you should also consider whether reading the name 25-75 times an hour will annoy readers.Because of the cold ‘br’ sound, Brian will probably grate readers more than Harry or Gary. Single-syllable names are fine, but not all are created equal.Agent Black is more kempt, septic and fits more with what we imagine a federal agent should be like.
I hope that readers subconsciously associate respectability with conformity.
If you compare Joan to Jane and Joe to John, Joan and Joe are usually stronger because they end more pleasantly.