You should look up some stats from 2014-2016. Norv has made this team depend almost entirely on a runningback.
Obviously after playing Tampa once they realized that feeding Christian wasn't going to work against the number one rushing defense, that was even doubling a runningback in coverage. They changed the gameplan up this week, and it worked well. Samuel and Moore were featured this week, and Christian received fewer touches.
This isn't news, just look at the Christian MVP talk from last week, and how many were mad that he was getting overused up until this game.