I'm about ready to start writing the revised draft of my story (though, to be honest, it's quite different from the first draft to the point that I wonder if it might as well just be a new first draft). I have a lot of the details down, with the main characters figured out and a definite idea of where the book will end. The problem I'm having is with putting it all together in a structure that feels coherent. For example, in my current outline, one of the main characters is the focus of most of the beginning chapters, with the other two leads not being introduced until quite a bit later. This is mostly because a lot of important details of the character's life take place before the main story starts. The other characters will have flashbacks, but their pasts aren't nearly as fleshed out as the first character's (at least, not in this book). However, I'm worried that people will be put off if I introduce two main characters late into the story (I'm not sure how late, but no more than a third of the way through). What do you think?