Barry offers more going forward because he's one of three centre midfield players, one to two of which always sits back. As a midfielder Xabi's game is about making plays more than goals and assists at present because Gerrard is the one going forward. Xabi is all about the passing, setting up attacks from midfield and looking at those statistics he's better at that and I'd bet he has a much better long pass success rate. It's easy to pull up statistics to make someone look better if the statistics are out of context.