In 23 games, they've scored 3 goals and given up 3 goals while maintaining a slight possession edge and high danger chances edge.
Is it a pretty low event line? Sure. But at least they're not bleeding chances, and it's the most productive of any combo of fourth line players, including substituting Nieto for Harkins.
Meanwhile, putting Smith back on Malkin's line and on the first power play unit screams, "OK, show us you want to be here and be productive or we'll ship your ass out at the deadline."