Liljegren over Sandin all day, every day. 
- GreatGigInTheSky
I believe strongly that a young defenseman will prosper when paired with a stabilizing partner. When Muzzin was healthy, it benefitted Holl to the point where he has been considered a legitimate top-4 option. When Muzzin was healthy, Holl was. When Muzzin was not able to lead that pairing or faltered in his play, Holl was not sufficient enough to compensate for those failings and was, as expected, exposed.
In this past season, Liljegren and Sandin paired together relatively effectively. They had an xG% of 65% and were +5 in 242 minutes of ice together.
Sandin was also paired with Dermott (218 minutes; +4) and Holl (132 minutes; +4).
Liljegren was paired with Giordano (181 minutes; +4), Rielly (145 minutes; +4), Muzzin (119 minutes; even) and Dermott (119 minutes; +1)
It wasn't until Liljegren was paired with Giordano that he really started to accelerate his game and improve his play. He is a year older, but had more development time because there was no real push to accelerate his development.
BTW, for the above, I excluded any pairings that played less than 60 minutes together - so Sandin's poor showing with Rielly or his flailing right-side experiments weren't considered.
My point here is that I don't think it's as simple as "Liljegren over Sandin all day every day". I think Sandin will likely be better than Liljegren, but he needs the opportunity and the partner to help him do so.
