Perhaps we'll see fewer two-RB sets (per Football Outsiders)

Yup. Sometimes you have to run the less efficient, less effective stuff in order to set up what does work.

That being said, it's still reasonable to expect Kamara's work load to go up a bit, meaning fewer two back sets.

There are so many factors to this that you can’t really look at those numbers.

As you said, some things are to set up others, Sometime you just want to play bully ball and ram it down their throats which pays off later in the game or maybe you got up by 24 point with 11 personnel and now you’re in the 4th and just want to run the clock, most of us realize you don’t wana just keep throwing the ball, not to mention, in this situation, the defense knows you’re running the ball and lastly, 3rd and short and goal line, you can’t really be very productive when you just need a single yard.