Subban had more 5v5 defensive zone starts and slightly more primary points than other top dmen. That is the sum total of the argument in favor of him for Norris. Look at top defensemen around the league and you'll see that many, if not most, carried around lesser partners. The credit Subban gets for carrying around the "ineffective Emelin," is over the top IMO. Worth pointing out that Hedman's most common partner was Dotchin and Doughty's was Forbort. I really don't believe that Emelin is THAT much worse of a player than Dotchin or Forbort are currently.
Subban had a fantastic season against relatively weaker competition. PK played the 4th toughest 5v5TOI% quality of competition among Nashville dmen at 29.12. For the record, Josi was #1 at 29.30, followed by Ellis 29.25, and then Ekholm 29.18 before Subban. Doughty and Hedman both played significantly tougher competition that Subban with 29.5 (!!!) and 29.27, respectively.
"One of these things is not like the others, one of these things doesn't belong!"
I'm not a big fan of that QoC TOI% stat, but yeah you have to give credit to Doughty, he plays very often against the other team's top line. But the difference between Subban's 29.12 and Hedman's 29.27 is not very significant.
And if you really use QoC TOI% as a reference, then you have to look at QoT TOI% too.
Subban: 27.57
Hedman: 28.05
Doughty: 28.44
Josi: 28.28
Subban played with significantly "weaker" teammates than the other finalists, and I included Josi too, for good measures. The difference is much bigger than the QoC TOI% difference.
Not saying Subban will win, but I think the QoT argument is in Subban's favor.
(The thing I don't like with QoC TOI% though, and I mentionned it in the past, is if you play against McDavid, and he plays with Slepyshev and Lucic, your QoC TOI% will not be very high, yet you're facing arguably the toughest competition in the league. So I believe there's a margin of error that you have to consider)