Regarding Di Maria/Dybala, at first I was really hesitant about Dybala as all I saw was shades of Di Maria, however after some thought I do think there are more differences here than similarities in this case.
Dybala wants to stay at Juve, but Juve don't want him - same as Di Maria, however;
Dybala doesn't appear to have his heart set on moving to a different club though, as Di Maria did with PSG. He was all set to move there except they couldn't balance the books with FFP that season, they likely told him they would attempt to buy him the following summer, which they did in the end. This isn't the case with Dybala, he isn't being courted by anyone.
Dybala knows he can stay at Juve if he wants to, Juve seem to be accepting his wishes, unlike the turnips at Real - though it will mean he will not play very much, so he might very well decide it is better to be playing at United every week and perhaps being apart of something special than warming the Juve bench (and all the while banking significantly more each week at united)
As for the South American part, is it possible that now with compatriots Romero and Rojo here, plus some Spanish speakers and his good mate Paul that he might find it easier to settle in. I remember hearing that De Gea is friends with Aguero, so maybe they can all have some dinner dates together at Wings to help settle our new favourite Argentine.
And the final difference is that Dybala doesn't seem like a complete fanny!