his run in 1992 was scary as well, Agassi had a perfect movement and shots from the baseline for grass. No volley, a poor serve ... and still ... And it was all natural, no preparation for that, just his game naturally.
HIs baseline-game was perfect for the 90´s fast grass. No long backswings and he liked to take the ball so early that having little time didn´t really bother him as much as other baseliners. Great return of serve, too. But like you said, it was all natural to him, it probably would have been nearly impossible to play like that as a result of adaptation, it was just his game.