I don't put much stock in +/- , E +/- is more informative, as is scoring changes for and against, and especially high danger scoring chances (HDSC).
Hagg and Ghost are our worst defensemen at ES.
The same people who castigate Hagg let Ghost off the hook even though his HDSC net percentage is just as bad (i.e. he gives up far more with bad decisions and defense than he makes with his offensive skills).
And watching both of them, it's not an accident, Ghost makes numerous mindfart bad passes and loses the puck with no help behind him, Hagg struggles handling and clearing the puck out of the D-zone under pressure. The difference is that one is a rookie, the other a 3rd year player who is almost 4 years older.
Ghost however has value on the PP that Hagg can't provide, but at ES both players' minutes should be minimized.