i really dont have an answer to this.
when slams is not the definitive measure, it becomes really difficult to compare players. you can have all sorts of arguments, who he played in finals, h2hs, master wins, all surfaces, etc,etc.
kuerten at 3 slams it doesn't seem to make sense to rank him below a 1 slammer. in that case he should at least be higher than Roddick. then we have roddick who i believe played the toughest competition compared to hewitt/safin (roddick met GOATing Fed in all his slam finals), and obviously hes the most consistent of the three.
yeah i too would take hewitts career, in these rankings im trying to obtain greatness and that itself is subjective.
tbh its very hard to split some of these players, I prefer to see them as one group in the grand scheme of things.
Yeah totally see where you're coming from & logically 3 Slams should automatically put you ahead of certainly 1 Slam winners & 99% of 2 Slam winners.
In case of Kuerten though we really are talking about a guy who only excelled on a single surface in an era where clearly the best player seriously struggled on it.
Agree with your comments on Roddick & that's why I think he deserves some bonus points beyond what you might typically afford a single slam winner & why I'd actually rate him ahead of Kuerten.
Like you say it's all subjective & that's the fun of it!!