You're right - the thing to draw conclusions from was watching him last season struggle with very basic things on the power play. That was 8 months ago, so no one but me remembers that. Now we just have the numbers.
The power play was not good without him, it was certainly worse having him on there. Remember, I went through every Devils power play since 2007-08, and it's not like the Devils have had great 2nd PP units in the last decade+. It's just impossible for him to be improving the Devils' PP relative to just a basic defenseman.
It's a small HORRIBLE sample. It's like a goaltender having a .750 save percentage in 4 games. Yeah, it's 4 games, but it's a .750 save percentage - the goaltender is probably getting unlucky, but he also must be failing to make some basic stops. Mike Matheson had a 2.57 xGA/60 in 2018-19 - that's the most recent time anyone had something like that, most years no one is going above 2. The Devils bled chances with Nemec on the ice, and the reason why xGA is Nemec's fault more than anyone else's on the unit is that he is the player most responsible for the breakout and keeping the blueline on the PP.
If Nemec plays like he did today in future games, I'll feel better about him on the PP.
Looks like 20yo defenseman can learn how to survive in some role. Im not telling to pit him above Hamilton or Luke but he definitely has actual skill to protect blue line. Without practicing he will not sustain it and will not balance it. Because in this game he looks like he can learn something.
And even third pair PK role is still a role for Nemec too when Pesce will return.
It works well for Casey too. Until he can play in the limited role, I don't see any reason to not give him more opportunity to learn how to play against breakaways, patrol behind the net, learn how to control D zone against cycling and work on other aspects of actual defending where he isn't perfect now. Because for limited role he is good enough. Yeah we will se some games against Panthers or Leafs or even Caps where he wil be loaded by physical players, forecheck, fast moving of the puck or will work against players who can shoot in different situations- but again, smaller role, less amount of teams who can really make the life really miserable for third pairs.
Until Casey can - he should learn how to play NHL games. Until Nemec can, he can learn how to play a role in pp. Btw even with Luke returning, I don't see 8 better forwards to play in PP. I would even think about 7 better forwards to play above Dougie, Luke, Nemec and Casey, but its hard to imagine all four in the roster inthe same time when everybody are healthy.