When comparing career accomplishments, the most weight should be given to (1) number of slams, and (2) weeks at #1. Other criteria like masters wins, YEC wins, etc come after.
Rafa is not going to come near Sampras in terms of weeks at #1.
So the only way he can even be in the discussion to be considered more accomplished than Pete is if he ends up with 15+ slams.
As to whether that is possible: I think it is possible, but not likely. Maybe a 20% chance.