If you like Tony Hillerman and I sure do, you need to try a Thurlo book. The Thurlos are a married couple who write about a female Navajo police lady. They write on the same book but not the same chapter at the same time. They have offices on opposite ends of their home just across the Rio Grande from here in Corrales, NM.
I envy their ability to do this, if they don't coordinate better. I once wrote a Fan Fiction story about a TV show, with five other writers. It was a massive pain to get most of them to post their assigned scenes, to see what the last had posted, and how to move the fic along without getting too disconnected from the story.
I then wrote another fic or two with one or two other authors. Then, my remaining 26 fics about that show were written strictly alone. I had learned my lesson about co-authors.
I am trying to complete my first commercial novel this year. it is also a private effort. You have to know where the story is going and have the same mindset and ideas for it to succeed. I was amazed that our collaborative efforts in those fics turned out as well as they did, although one guy didn't like the way the project progressed and dropped out about midway. Had most of the characters not been pretty well defined by their roles on TV, I doubt that we'd have achieved acceptable results. I did get two characters together romantically who weren't in that circumstance on TV. That initially ruffled some feathers, but many readers later said that they liked the way it turned out.
I have just been wheedled by one reader into writing another fan fic about that show. If she wasn't cute and an old friend who I helped with her graduation paper from high school (required in her nation), I probably wouldn't take time from the novel to do it. I'm often a sucker for a pretty face. But she impressed me by posting reviews of my fics in which she said that she seldom cares for original support characters in other authors' works, but likes my characters. (On TV, these would have been guest stars.)
Anyway, collaborative writing isn't easy, although it's done.
Do any of you read David Lindsey's books about Houston PD Homicide Sgt. Stuart Haydon? I especially suggest, "Spiral", "A Cold Mind", and "Mercy." I think most of his books are still in print in paperback, although your bookseller may have to order them. Many libraries will have them.
John Sandford is also good, if quite different. He does involve Dem. politics, being a former newsman from MN. But his stuff is pretty solid, without excessive fantasy.