Quoting: papishark
Hes a better player than Hall was at the time and is a center which typically return much more than wingers?
There's no way Hertl was better than Hall
Just looking at points, in each of their last 5 seasons prior to the trade
Hall: 0.93 points per game
Hertl 0.73 points per game
And if you look at the past 3 years prior to the trade
Hall: 1.11 points per game
Hertl: 0.87 points per game
Not to mention, Hall won a Hart during that time
So no Hertl is not the better player.
The only valid argument is that Hertl is a center. But that doesn't make him much more valuable than Hall