For JS I would rank them:
Murphy
Fred
Murray
Murphy has done some good things and more importantly, some that a coach absolutely loves (courageous marks, pressure, etc) and I wouldn't underestimate the impact of a rookie that is doing good things in an awful team.
Fred has shaky JS but is scoring well while in, and has taken his opportunity meaning if other injuries pop up he's definitely on the radar.
Murray took a while to crack in and was thrown around a bit on the weekend with some time up forward. Think he falls out of the team in the next few weeks so don't think he plays long term or makes any real cash.