Totally agree on Chaney - I think he's the most talented and has the best full package of traits you want in a RB that we have. Really hope he makes a 100% recovery.
For Knighton/Thad - I actually see their styles reversed, and it doesn't make sense because their styles don't match their body types.
Knighton is more the one-cut, look for contact type runner. If you rewatch his highlights, he makes one cut then runs full steam ahead. He's trying to run through defenders after his first cut more than he is trying to avoid them. His body type says shifty, but his style is more straight forward physical.
Thad is more a big man with great feet. He still has very few carries, so I'd like to see more, but I think people are going to find he's much more in the avoid and slide off tacklers than he is run over people type (I'd like to see Knighton be more like this). Thad is kind of similar to how Gus Edwards was. The body type says physical punisher, but his style is more trying to make defenders miss. Speed is probably his biggest drawback.
Lots of talent with potential - hopefully it all starts coming together this year.