OK, lets look at it from this POV. Thuram has been one of the best Serie A defenders, the league where the best defence is played without question, for 6 or 7 years, who's won the World Cup and the European Championship and been considered one of France's best players in that period, not to mention that he scored two goals in the WC1998 semi final against Croatia.
Hmmm, yes, I would say he's better than neville.