In LOTR, Tolkien puts concurrent stories in different books Book 3 follows the rump of the fellowship and its battle against Saruman. Book 4 follows the ring bearer and his battle with Sauron. In my story an event causes 3 groups of characters to take 3 different paths. This might be a question only I can answer but which is the more approachable method of dealing with this: Stick to the chronological order? Write each story separately until a possible regrouping? I like the idea of and consistency of 2. but I remember how frustrated i got when reading LOTR so when I read it for the first time, I skimmed Book 3 to what I regarded at the time as the main plot. Any thoughts?
I'm in favor of #2 because it minimizes interruptions in each story. I have the opposite problem you had: when I'm reading a book where the main characters are separated, and each chapter alternates between them, I'm more likely to skim past the boring characters until I get back to the ones I like. With a big self-contained block of story like a book subdivided into "books," I don't need to rebel against the author for making me wait to find out what happened to somebody else.