There is a fab five.
Kohli, root, Williamson, smith, babar
Babar is not at the top of his game yet imo. I feel that his strike rotation needs to improve, and he probably will develop a top gear as well. In 2 years time I see him to be at his prime.
Here is how I would rate the above five.
Smith
Defence 9/10
Top gear 8.5/10
Consistency 9.5/10
Impact (a) Match winning ability 9/10 (b) Role in the batting line up 9/10 Overall 9/10
Manipulation of the field (a) Strike rotation 10/10 (b) Boundary Hitting 9/10 Overall 9.75/10
Running Between the wickets 9.5/10
Overall Score: 9.2/10
Kohli
Defence 8.5/10
Top gear 9.5/10
Consistency 10/10
Impact (a) Match winning ability 10/10 (b) Role in the batting line up 9.5/10 Overall 9.75
Manipulation of the field (a) Strike rotation 9.5/10 (b) Boundary Hitting 10/10 Overall 9.75
Running Between the wickets 10/10
Overall Score 9.58/10
Williamson
Defence 9.5/10
Top gear 8/10
Consistency 8.5/10
Impact (a) Match winning ability 8.5/10 (b) Role in the batting line up 10/10
Manipulation of the field (a) Strike rotation 10/10 (b) Boundary Hitting 9/10
Running Between the wickets 9.5/10
Overall Score: 9.04/10
Root
Defence 9/10
Top gear 8/10
Consistency 9/10
Impact (a) Match winning ability 8/10 (b) Role in the batting line up 7/10 Overall 7.5/10
Manipulation of the field (a) Strike rotation 9.5/10 (b) Boundary Hitting 9/10 Overall 9.25/10
Running Between the wickets 9.5/10
Overall Score: 8.71/10
Babar
Defence 8/10
Top gear 8/10
Consistency 9/10
Impact (a) Match winning ability 7/10 (b) Role in the batting line up 9.5/10 overall 8.25/10
Manipulation of the field (a) Strike rotation 8/10 (b) Boundary Hitting 9.5/10 overall 8.75/10
Running Between the wickets 9/10
Overall Score 8.5/10
So the Order imo is
Kohli 9.58 > Smith 9.21 >Williamson 9.04 > Root 8.71 > Babar 8.5
The average of these score is around 9.008, while the standard deviation is 0.38. Kohli being 1.5 s.d's above the mean shows that he is around 87% (if a normal curve is to be assumed), which mean that is by far the best atm. While Babar being 1.31 s.d's shows he has to improve his game a lot to be truly considered in the same bracket, an argument on his part would be that he is just 24, and has time on his side.
PS: ODIs only