What makes you say Xavi had better vision? Scholes would regularly find players and build up attacks. What makes you say he had a better weight of pass? Scholes rarely, if ever, misplaced a pass and long range passing is much more difficult, which even you acknowledge was better. I think you are judging Xavi based on teams he played for and their style i.e.\ Barcelona & Spain and possession based football. If Xavi played in our midfield instead of Scholes, we wouldn't have dominated games in the same way that Barcelona and Spain did. You make a claim that Xavi would control any midfield regardless of the opposition. Xavi was lucky to have never played against Keane who would have knocked him the feck out. Keane dominated a match in midfield against Zidane, Deschamps and Edgar fecking Davids.
I get that Xavi was a great player, and yes, there is an argument to be made he was better than Scholes, but its wrong to suggest he is some magical man who could do anything regardless.