Nobody's getting the Calendar Slam ffs. Laver only managed because 3/4 were grass and he had seriously weakened competition even for the time.
What are you on about mate, he faced top players everywhere. Newcombe, Ashe, peak Roche (tough luck), Smith. The only weak point was RG, as Rosewall was getting old for clay and didn't play as well as before, per Laver's own admission.