The pop trio - Mickey Parsons, Dan Ferrari-Lane and Greg West - were selected for the Live Shows last night, alongside hip-hop duo MK1 and fellow boyband Union J.
When asked by Xtra Factor presenter Caroline Flack if he thought GMD3 could topple One Direction, Walsh backed his new group to go global like Harry Styles and co.
"From the very first audition I knew they were something special. They were just naturally amazing vocals." he said.
"Vocally yes [they are better than One Direction]. They are world class."
GMD3 have asked their fans to help them come up with a new name this week, ahead of the Live Shows launch. The group claimed that their current title was confusing and took on board criticism from Sharon Osbourne that the name sounds like "an infection".
The X Factor Live Shows launch this weekend on ITV1.
[X Factor Live Shows Final 12 - Photo Gallery]