I wouldn't say that Barber is underrated as he is the only one of this group that's in the hhof.
Larouche was the first player to score 50 goals for for 2 different teams and almost scored 50 for a third team when he finished with 48 for the Rangers.
Some of the other players on this list - I'm not sure whether they were underrated - few of them had one or two career years, but that's about it.
Some of those guys were well known at the time, but are mostly forgotten nowadays.
Rick MacLeish is another that comes to mind.
When people talk about former Flyers great, they are more likely to talk about Clarke, Leach, and skip to the more recent names.
When I hear the name Barber, I mostly hear it coupled with the words "art of diving" and even "obvious dives". There was a lot more to his game than the dives, but that's the first thing that comes to mind.
What does Larouche in, the two 50 goals seasons are scored with Mtl where there are so many greats that he pales in comparison and Pittsbugh where future glories of the team and some of its players obsucres past accomplishments of the Larouche, Pronovost, Lowell MacDonald line with the secondary scoring of Syl Apps, Ron Schock, Ron Stackhouse etc. That Ranger team was also a pretty bad team, so he may have been close to 50 goals with three different teams but not having any longevity with the same team might leave him a little forgotten.
Just personal observation is all. Feel free to disagree.