Ummm, you're right, I had not thought about that.
In fact right now I can not think of any player ( outside the top 4 ) winning a GS tournament any time soon.
So maybe you're right and they will end up with more GS total than I previously thought.
i know. Because when I looked and thought about it, I really can't put a name to a GS winner outside of the 4. Unless by way of a tragedy, Roger and Rafa retires, or anyone of the top 4 gets sick or someting. So, unless something of the extraordinary happens, Im thinking, these 4 will still get the majority of the SLAMS in the next 4 yrs at least.
Maybe Delpo, Tsonga, Berdych or Ferrer will snatch a Slam or 2. Outside of them who ? Wawrinka, Almagro, Tipsy ?
tHE YOUNG ONES ? I watch Raonic today, and his game is not ripe to win a Major. His defense etc is too weak. He barely snapped a win against Chardy. Hopefully, he improves. Nishikori ? Remains to be seen. Serve among other things are in question. Isner or Querrey ? Nahhh. Tomic, Harrison ? double nahhh
But maybe I'm wrong and a prodigy will just come out of nowhere.