As objective as possible the framing of their line would be that Leonard was the dirty work guy who dug pucks out, played more direct, went to the net, and got open for shots. Perreault was a playmaker often looking for open teammates, making quick puck decisions, and working to move the puck around, while Smith was a little bit of a combination of those two as the center on the line and maybe tilting a little more towards the type of game Perreault was playing.
They worked very well together, and all three benefit from playing with each other. We’ll see how each does when they aren’t playing together. Smith will be apart from the other two this season, and the two wingers will be without their center.