Depends of whatever disparity there is between Canon when juxtaposed with Legends.
If we assume it isn't big, GG wins emphatically. If we assume the gap is monumental - or at least very noticeable, Nihl has some wiggle room for a winning argument in his favor.
URS
UrsumelesTraitor
👆
It also depends how much we interpret in GG vs Maul
Spoiler: and GG feat against Kenobi in the Utapau episodes