He shouldn't have sent somebody like Spilotro at all, regardless of his friendship with "the golden jew."
I have heard from people in Chicago that Spilotro was pretty much a nobody and would have never been known if it wasn't for Casino (and the book). I just think they could have sent somebody more responsible and/or trusted to oversee such a big racket.
I have no idea where you heard that. Spilotro was one of the more infamous Outfit enforcers in Chicago long before he went to Vegas.