PK Subban was a better player than Shea Weber, that's how. Pray tell, since the two were traded, who was nominated for the Norris and made year end second team All Star? Take your time, there's no rush to answer...
PK Subban was the best d-man on two teams that should have won the Cup had Pekka Rinne not choked like the Finnish incarnation of Marc-André Fleury. Nashville instantly won as many playoff series in Subban's first year there as Shea Weber did in his entire career. In that first year, Subban was on the ice for only two even strength goal against during the whole playoff run.
Weber, meanwhile, who was traded explicitly to put the Canadiens over the hump in win-now mode, has led the team to 6 meager playoff games in 3 years. Sounds like a typical Shea Weber year in Nashville, to be perfectly honest.
And Subban's contract ends in three years in his early 30s as opposed to Weber's contract that ends in 7 at age 41. Weber's only advantage is that the caphit is $1.2M lower. It's not difficult to understand who has the better contract, it's clearly PK Subban.