It depends from the Game, it has nothing to do with who is doing the HT
I mean it's an accomplishment for Katy that she was the headliner of the most watched show, but she isn't the reason for that.
I'd be happy for Gaga if she does it and I'll brag, but I still know it's the game.
During Katy's HT the game peaked 3 times with higher numbers than the HT.