I truly think there is a big difference between a journo and a commentator. Or at least there used to be. Both have to be highly knowledgeable and credible of course.
The Commentator calls the action of a game and adds to the theatre of what you're seeing on the TV or hearing through the radio waves. They call the here and now, with both insight and adding to the emotion of the game.
The Journo writes narrative of the match and current affairs of the sport. The backstories, the scoops, the controversies, opinion pieces. They will express their views unashamedly for you to agree/disagree in the pubs with your mates to argue.
For mine....
Credible Commentators. Andrew Voss, Ray Warren, Peter Sterling, Andrew Moore, Andy Raymond, Michael Ennis, There are many other good "presenters" but not commentators as such, eg Lara Pitt.
Credible Journos. Andrew Webster, Neil Breen, Barry Toohey spring to mind.
I personally can't stand when commentators turn journo's throughout the call in a contest to be "outraged" at refereeing decisions. Happens so much these days and it's the biggest turn-off to watching modern day NRL for mine. Anasta & Johns are the worst here. Many others aren't far behind.
The only bloke who I think has/can transcend the boundaries between the two is Phil Gould. Although lately in commentary he's erred towards being the journo too much.
A divisive guy is Paul Kent, I gotta say I really like him on the Matty Johns Podcast and Triple M's NRL when I've listened. But then when he gets on NRL360 all of a sudden the voice goes up 3 octaves and everything that seemingly happens in the NRL is a farce.