Reus and Sanchez both work tirelessly off the ball as well but the big difference is they offer 100x more than Willian in the final third... IMO he's a vital squad player and does reminds me of someone like Ji Sung Park, a player who can play in the big tactical 'chess' games but is not really a regular. Having ineffective attackers in the final third will cost us in the CL, look at Real, Barcelona and Bayern.. goals everywhere. If Hazard and Costa both have a poor game who's going to score? it wont be Oscar or Willian, thats for sure.