If you get B-beck, pull the trigger. If not, pull the trigger. Winners have to take risks and the benefits are pretty high. You have no control over injuries, players crapping the bed, etc, but Newton is the starter, no questions. And even if his passing falls off a bit, his rushing will likely cover for a decent amount of that.
Be bold.
btw, with performance scoring, you're likely looking at more than 2 pts per game from Maclin.