I really think changing the ratings for running backs like imac and Armor suggested, Fight For Yards - Yes, Cover Ball - All Hits, and High Motor - off is the key. With not adjusting their ratings they still hit the holes but had the moves still.
I played two games with the RB edits suggested and held Chrisitan Mccafrey and Saquan Barkley to a combined 72 yards on 43 carries. Played two more games with just those changes and both teams (Barkely again and Seahawks great stable of mid 70's running backs) and both teams had almost a 150 each at the half. I stopped at the half of each because I wanted to try another team. It was ridiculous and great. So much show I will probably lower CPU run block to 75