Tony has the advantage in some poses and might have the most potential, but looks to have some deficiencies that will have to be addressed to win. Hasn't realized as much of his potential as Kai, doesn't have the same refinement in terms of detail, separation or muscle maturity. Also some big gaps in balance, lacking in areas like tris and calves where it's very obvious. Should also bring the thighs down a bit, a little too big for the rest. Then there's the posing advantage for Kai.
If he wants to be the best he'll have to improve and refine those areas that detract from the rest.
The height advantage is striking; in general i think a BB of 5'10" or more has a real advantage in aesthetics as well as height when the physique matures.