Just looking at Durzi (Durzi usually plays with Roy, so this is essentially for the pairing):
The first line's relative possession numbers tank when they are on the ice with him.
The second line's possession numbers improve a bit.
The third line's numbers see a moderate increase with Durzi.
The fourth line's numbers see a substantial increase with Durzi.
It makes sense, really. Kopitar's line thrives on predictability which is why Fiala wasn't working. Durzi is Fiala's equal when it comes to random shit on the ice.
The second line is more of a rush line, so Durzi's play helps there. Granted Durzi won't see the tougher D assignments, but there is a positive effect. Note that line 2 still holds its own without Durzi, while Durzi's numbers drop substantially when away from line 2.
Can't really get a read on the 3rd as it's been a revolving door, but Durzi is generally positive with them.
His greatest impact is with the 4th line. Lizotte and Lemieux like to generate chaos on their own so he fits right in.
These are possession numbers but similar effects are seen with scoring chances for and against.
So Durzi/Roy don't play well together but they aren't really dragging anyone except the first line. Their possession numbers against are not good at all considering the competition they face.
The biggest drags on linemates? Kaliyev is the worst, followed by Byfield. Kaliyev's numbers drop off a cliff when he's away from the two L's. The best impact on linemates and high danger scoring chances? 4. Danault, 3. Vilardi. 2. Kupari (small sample size, but he's been impressive), and #1........... Brandt Clarke. Clarke causes far more danger than he allows, and that's with the lowest offensive zone start numbers on the team. And he's still got positive possession numbers. Clarke isn't really being all that protected or sheltered, pretty impressive.