I do enjoy how moderators inflame debate, then infract when the debate gets too hot for them.
Smith remains a guy who scores unbelievable amounts of runs in home conditions against attacks that suit him; he's been found out in trying conditions by bowling attacks that know how to attack him and if he batted most of his time in the conditions that Root or Williamson bat in at home, his average would be 45, not 58.
The only statistically significant sample he has outside of Australia is England where he averages 43.3, so the talk about him being as good away from home hasn't been proven yet. What he is tremendous at is making hundreds when he's set, something that at the moment seems to be out of the reach of Root, Williamson and Kohli. It boosts his average significantly, however, his runs to wins ratio is far worse than almost any other top Australian batsman since pre Border.
So fair play to the guy, he knows how to make it count when he's in, but he has the type of technique that will always see him struggle against the moving ball; he's been extremely fortunate that for the past two to three years, the batch of Kookaburra balls have simply not done as much as they used to, this is evident in the fact that swing demons like Starc, Southee, Boult are all struggling to make the thing move for longer than a few overs.
But if you're really assessing who the best batsman of those four are, let's see what happens when he has more than a few test series against the Duke.