Rattie is the highest upside of all these guys and it isn't even close. If someone goes down on the right side he's likely 1st or 2nd callup. Lots of talent but hasn't been able to put it together at the NHL level.
Stanton had a couple decent seasons with the Canucks. Could conceivably be a callup/injury replacement. NHL experience is a plus.
Callahan is a VERY good AHL forward. In classic Detroit fashion he's played most of six seasons in Grand Rapids. He was great in the playoffs for them and should push for a bottom 6 spot with Pakarinen.
Seems like Pasquale has been around forever, but he's only 26. Should push Ellis for starts - he's a .920 goalie at the AHL level.
Downing I don't know much about. Decent AHL centre. Had a good year in 15-16, regressed a bit last season. Decent size.
Ferlin was a good prospect at one point. Chia drafted him in the 4th round. Must have seen something he liked. He's got size and isn't shy to battle. Missed just about all of last year due to injury. Has played a grand total of 25 AHL games the last two seasons, kid can't stay healthy. Tough luck.
Last but not least, Keegan Lowe fulfills the 'one ex Oil King in the organization at all times' requirement. Very tough and steady at the AHL level, worthwhile depth guy to insulate the rookies.