Does one thing always mean something else too
After watching Herbert's highlights...
His running style seems like a perfect fit for the Seahawks line and offensive scheme. He has a good sense of where the holes will be and bursts through them. He doesn't have Walker's top-end speed; there were several runs of his where Walker's speed would have housed it. I'm seeing a RB that is halfway between Charbs and Walker, shiftier than Charbs, and some of Walker's wiggle without his top end and without quite as much dancing before getting north and south. Once Herbert gets moving, he is hard to bring down and moves the pile if it's DBs and smaller LBs trying to tackle him.
What I think it means...
* Charbs will be tender and not 100% for a while
* A smashmouth rushing offense like Kubiak is building for the Hawks needs multiple healthy RBs available
* Hawks view Herbert as potentially an upgrade over Holani
* I noticed that Herbert was targeted plenty in the passing game, so when he's in, it preserves the dual run/pass threat
* Herbert seemed very good at following his blocks and should LOVE running behind the blocks of Robbie Ouzts
* Herbert's highlights didn't show any of his pass blocking/blitz pickup skills, but I have to assume the Hawks scouted this aspect and found it at least satisfactory.
All things considered, this looks like an excellent signing (assuming they DO sign him) and I expect Herbert to be placed on the active roster soon and get perhaps 10 snaps a game, plus special teams snaps. Looks like he'd also be good on special teams.