Writing is a Socially Acceptable Form of Schizophrenia

So, the first time I read the section in Donald Maass' Writing the Breakout Novel Workbook about combining characters, my brain rebelled.

"But, but...I need those characters! All of them! Combining them together will destroy them!"

Now I'm starting to see that combining them may in fact make them stronger.

I'm in the rewrite phase of ze 2YN and I've been having a big problem with my MC's love interest (who happens to be a ghost). She just didn't seem to come to life (pun very much intended). If anything she was just kind of there, urging him on when he needed a nudging. My MC has a former FBI partner (also a ghost), who is way more important to the plot, has many more scenes, and is more emotionally involved and causes tension.

Why not combine them?

It seems so simple now. You know, after rewriting about a third of it from scratch.

Of course, I might think this is a terrible fix and change it again...