I'd say peak Federer. During his prime peak he was very good at neutralizing and go toe to toe with the heavy hitters because of his insane footwork. The other player didn't even know what hit them and the match's already over.
Fed would pull him off the court, make him uncomfortable, and hit winners all day. It's insane that this question is even being asked. Peak Fed was incredible.
And honestly peak Fed was extremely good at 'digging deep' against these kind of players. He never lost because his opponent redlined (except Safin 2005 AO). He'd only lose to retrievers who'd force him to hit several extra balls.
Newcomers to tennis now aren't going to think Federer's level of play is especially insane, but that's because he's nearing the end of his career and he has declined significantly. At his peak, Federer was absolutely unstoppable. I used to dislike him a lot more than I do now because he'd always beat my favourites. The ONLY time he lost in a HC or grass slam between 2004-2007 was against Safin who was playing the best tennis of his or most other players lives, and Federer still was one point away from winning that.