I don't understand how Griezmann and Dybala would be solving Barcelona's problems. That just smacks of 'throw money at the situation for it to go away '. If they were selling Suarez, I'd understand purchasing one of Griezmann or Dybala, but since it's Neymar leaving, their team would become even more unbalanced. You have Dybala who already plays in the same areas as Messi, even if they moved Messi central, they'd have Suarez LW!? I suppose it could work if they switched to a Narrow 4-4-2 diamond with Messi at the Tip and Suarez and Dybala up front, but where is Griezmann?
Barcelona already had enough problems as it was without having to replace the best lw in the world. I personally think they should bring back Thiago with part of that Neymar money and it will go a long way to solving their longterm midfield issues. Given that Iniesta is no longer consistently at his best, I reckon Busquets, Rakitic and Thiago is more than sufficient to dominate 95% of their matches. If it functions well then I reckon they could get away with Deulofeu on LW. They could even bring back Pedro as a short term option until they found an LW suitable to replace Neymar.