Pretty unfair at this point to call Thiem, Medvedev, and Alcaraz "one slam wonders." True that each has won only one grand slam so far, but that phrase dictates that the players career is either over or very near its end, and that they never win another grand slam in their career. It is far too early in the careers of those three to make that determination.
No disrespect to these three players intended! I look forward to removing their names from this quiz in due course-- although I am worried about how things have been going lately for Thiem.