GW doesn't "beat" anybody higher than D-Tier except Kirby and maybe Pit / ROB. The character is ruthlessly overrated and only does well in areas with lots of MK players. Ironically it's the match-up a lot of GW players like to complain about the most even though the character gets mercilessly ***** in tourney by characters like Diddy Kong, Marth, Olimar and IC first.
Some of his +1 should be 0 or -1 [Pikachu, Lucario, Wolf], some of his +2 or +3's are actually +1 [Mario, Sheik] while the 0's vs Falco, DDD, ZSS and Fox are -1. His match-up spread is easily the most overrated in this match-up chart.