Part 1, explanation of the Bella Syndrome, here
When I say that authors cannot create multiple living characters in one story, I am not insulting authors. They, or I should say we, gave life to the lovable, dynamic, living characters that are the true heroes. We cannot write from the POV of these characters because they are alive. We will not write from these characters because it would damage them. Writing from them would cast them as a body for us to see in, not as a person with her/his own thoughts and will.
Despite not having written a novel yet, I can speak for this. I created a character I fell in love with. He is the part of me that I aspire to be: brave, action -driven, clever and sometimes, well, all the time, reckless.
The heroine is the opposite. She is incredibly hard to get to know. During her interview I came close to begging from her. “Just tell me anything about yourself.” and she finally started a story that helped me understand the relationship between her and the hero. Character interview tip: Areas in which your character offers more tangents is an area you may want to explore first, then gradually nudge them into talking about their story.
And I understood the relationship between me and them. I filled my hero with everything I want to be and my heroine with everything I fear to be.