Well I have to be honest, although I made a sarcastic comment a page ago, Ozil is miles and miles ahead of Dybala as a CAM. Even if Ozil is lazy for a midfielder, he still does more than Dybala who is a striker playing as a midfielder, really. But he is an actual #10 on top of it.
If selling Dybala is inevitable then it's hard to do better than Ozil on a free. I think it actually improves the team in the short-term.
But I would prefer we try Dybala as a #9 and if he succeeds, sell Higuain. Ozil behind Dybala is a better combination of talent and youth for me.
If the plan would be to go forward with just Higuain-Ozil then forget it.
Also, Pjanic was a good times player not long ago. But not anymore. I think every player under Arsene Wenger is more or less a good times player.