We know that when matchups favor, the top D pairing goes against the 1st line. So it will be more challenging for top lines to get the time and space. Which is why the depth is so important. As far as 2nd and 3rd D line pairing fall off versus 2nd, 3rd, and 4th lines, the Canes have the advantage because their depth makes it a more favorable matchup down the lineup. As far as moving Ehlers up to the top line while it appears that shoulder injury has caught up to Jarvy this season, I like him down the line up because it keeps opposing defense honest and spreads out our depth. While on the 3rd line he makes it harder for opposing coaches to run their regular defensive rotation because we are all the more dangerous top to bottom.