My thoughts -
Kohli - Already an ATG in limited overs, will end with 50+ average in tests but will probably fall just short of an ATG status, will be in direct competition with Sachin as the best ever Indian batsman by the time he retires and with Dhoni/Ganguly as the best ever Captain.
Smith - Assured of being an ATG in tests, will be a good to great player in LOIs but not an ATG, okayish captain.
Root - ATG in both tests and limited overs, but inferior to Kohli in ODIs and Smith in tests. This Ashes will say a lot about his captaincy.
Williamson - Would stay in the shadow of above three, "Is Williamson an ATG?" to be the most popular cricket thread in 2050.
Ashwin - Would not be an ATG if he fails again overseas, needs at least 2-3 match winning performances outside SC.
QDK - Would be over-hyped for all of his career, people would be disappointed once he finishes with great numbers which they expected to be even greater.
Warner - I think he is starting to turn a corner in SC, will end up as an a second tier ATG opener, but not an ATG batsman.
Starc - Waqar Younis - v2.
Hazlewood - Macgrath - v2.
Broad - Inferior to Jawagal Srinath.
Bairstow - I rate him higher than QDK.
Stokes - Would get punched in a bar in Australia by Joe Root once they are 3-0 down while Dave Warner sits on the side, sips his drink and smiles, would punch him back breaking off three of his teeth and would be thrown out of the team forever. People will wonder what could have been.
Hardik - ATG first name, average bowler , good batsman, probably an ATG in limited overs.
Moeen Ali - England will miss him when he is gone.
Ajhar Ali - ?????????????? Why are people not naming him???????????