One thing about Robinson that needs to be put into the context of the day was that he was also a nuclear deterrent.
For those of us who remember, the 1970's was a circus of violence. It was like "Escape from New York", and Robinson was a tall Snake Plissken. The Habs swept the two-time Cup champ Flyers because with Robinson, they proved that they could beat the Flyers in the alley as well as on the ice. Meanwhile, the Boston Bruins may have had the best collection of fighters in the league, but they didn't have Robinson. He automatically meant that absolutely no team in the NHL could intimidate the Habs.
Yeah, Montreal had Bouchard, Risbrough, Trembley and Lapointe - all players who could fight. But it was Robinson who was the great equalizer against teams that brought Schultz, Kelly, Dupont, Saleski, Wensink, Jonathan and O'Reilly.
Would Montreal have won those Stanley Cups while facing the bullies employed by Philly and Boston if they could have been intimidated. Maybe once. Possibly twice. Not four times. Of all the players who made them "brave", Robinson was the number one guy.
If that was all that Robinson could do, it wouldn't be worth mentioning. But you put that in with everything he did at even strength, and the great numbers he put up with limited power play time, and you can see that he was excellent at some things that some of the defensemen picked before him (Lidstrom, Fetisov, Kelly) were not. They didn't have to be because of the eras they played in. Robinson was called upon to play that way. It's very liberating when your toughest player is also one of your best players.