Di Matteo, Zola, Ravenelli, De Canio certainly come to mind not sure they have been any better or worse than any other European League in general such as Germans, Dutch, French etc in terms of settling in here!
Also Gaston is Uruguayan and they are meant to be the country that plays a style most closely asscoiated to European than many of the other South Americans! (i.e. more physical than the Brazils etc.). There have also been quite a few Successful South Americans in the English leagues Argentinians Braziliansa as well as other Uruguayans (Poyet and Suarez) so not sure what your point is!
He is only 21 a great talent and a long way from home so give the lad a chance and a bit of support to help him show his real ability!