I wouldn't expect you to be fluent in all things Devils, but for anyone that has watched them closely this year, Pavel Zacha has visibly turned a corner in his game.
His stat line from this year is virtually identical to 2016-17, but, peeling back the layers of the onion, Zacha's ESPoints/60 spiked to 1.35 from 0.82. He's a responsible, big player with a fantastic two-way game... strong on his skates, good awareness, hard to knock off the puck. His offensive game is still rounding out, but we've seen flashes... he has a heavy shot from the circles on the PP and is very good in transition.
Frankly, I see a lot of Sean Couturier in him. I'm not saying Zacha will have some monster 30-goal breakout one day, but they're similar players in both style and trajectory. As far as the plus I'd add on top of Zacha for Muzzin, I'm not sure I'd add a ton. I think it's a very good gamble for LA, and a no-brainer for NJ given their needs.
(And, for what it's worth, Hynes and Shero have referred to Zacha in the past as a winger. I think he only played C this year out of necessity, given the Henrique trade. I only mention this because 1LW was specified in the OP.)