The 4th RB played ST mainly because the top 3 RBs and TH7 received majority carries so it made the 4th back’s spot feel useful. The reserve LBs, DBs, DEs, FB and a WR should be filling the ST spots anyway. We need to carry 4 real RBs for Kamara’s suspension and injury depth to AK and JW. It allows AK to maximize his receiver roles more and keep him with fresh legs at this point in his career.