My issue with taking any RB in the top 10 (I would even go so far as to argue first round in some occasions) is the cost associated. Taking a guy like Barkley in the top 10 means that by his 5th year, if he's actually good, he's going to be costing you $10-12 million per year...which is an exorbitant amount to pay a RB.
RB's are value wise, really, really cheap. Why? They're easily replaceable, they get injured far more frequently than any other position, and they're just not that important.
You simply do not need an elite RB to win football games. Sure, it helps, but the cost associated isn't worth it. Zeke Elliot is a great RB, but Dallas would've been far better off taking Jaley Ramsay. Is Barkley really that much better than Guice, Michel? I don't think so...not at the opportunity cost. Leonard Fournette, is currently the 5th highest average salary for a RB and he's on his rookie contract. He most likely will be bumped down by Barkley, but it just depends on where Barkley goes. That's a crazy amount of money to pay for a position that just isn't worth it.
Really, when it comes to money, your three weakest positions are RB, ILB, and S. The draft should reflect that as well. You don't want to overdraft those positions, but especially with RB. Don't waste money on RB's.