The Raiders need a stud LB. They have spent a ton of picks on bad CBs. They also want a flashy WR for Gruden's offense. Their needs align exactly with Jacksonville's which makes this trade back highly plausible.
Competition for OTs is also interesting in this scenario. If one is taken early 1-6, then the Cards take one, the Browns and Jets will be desperate for the last elite OT. It won't be a great trade haul, but wouldn't be moving too far back either.