Oh, I hate this game. Would need more specifics about the rest of the team and the situation to pick just one. To be as effective as we want to be (more than just Coastal), I think we *need* both. If you watch Lashlee's sets from SMU and Auburn, you know there's a good amount of variation to what he asks his OL to do. What that means to me is we need different types of backs.
I think Knighton has the more immediate impact because he's a near perfect fit for what I expect Lashlee to do this season - keep things simple, spread the field, find matchups and utilize a lot of zone calls where Knighton's style is a seamless fit. But, if you really dig into Lashlee's more complex OL pulls, I think Chaney - especially as his body develops - becomes a perfect complement with Knighton.