Its baffling how many people confuse Songs's role. He was a 'shy' CM who played a B2B role as he grew in confidence and ability. His last season was a culmination of Wengers coaching and confidence in him when he successfully played as an all action CM/b2b contributing both in attack (majorly) and defense.
IMO some of Wilshere's best displays came alongside him
Selling him is an entirely different topic, though i think if we had him for one more season, we would have benefited tremendously