One manuscript asks a question and the other manuscript answers
www.thenextnovel.com
The pond novel has three main characters, but Anna and I both agree that, in this first draft, one of them is just much more compelling than the other two. This is because we’ve figured out more about his desires and motivations, and those elements are driving his story. The other two characters are more elusive, but I think we’re getting closer to unlocking one, and the answer was hidden in plain sight, in my other novel draft.
What an exciting discovery! It's like your collaborating with yourself.