playing Devil's Advocate (for this part specifically at least) Radahn actually has a stronger argument since he.. directly uses Collapsing Stars in a combat applicable manner (i.e. the same spell he uses to hold back the stars is a spell he uses against peer opponents like the Tarnished)GabrielGeneral Radahn
SB being mad they can move stars so they have to come up with some reason it doesn't scale to them at all
Gabriel doesn't do that, and is merely stated to have "other spells" on that level