I think that he probably is. Smalling is a bit more agressive, which makes him lose slightly more duels, but on the other side, Smalling attempts more duels than Fonte. On average, Smalling wins 3.46 aerial duels compared to 2.43 for Fonte, while Fonte has a better successful rate of 68.18% compared to 63.68% for Smalling.
I think that when it comes to aerial duels, the number of duels won is far more important IMO (Blind for example has the same percentage as Smalling but he wins only 1.25 aerial duels for match and anyone who watched the games realizes that he is far worse than Smalling at it despite the same percentage of aerial duels won).
Also, Fonte's ability on reading the game is nowhere as good as those players you mentioned, heck, I think that even Blind is better at it than Fonte.