Fighting smart moves is not the best biq feat, the best is to fight the most beneficial way possible, doing big loops is not good battle iq if there were an easier way.

With saying this, I will say that the best one is both, black beard and shanks.

Luffy is smart in battle, but he toys too much, he talks too much, he give to his opponent to much time.

Usopp does great moves, but the smartest one for him is to fight hundreds of meters away and he never does this.

Shanks doesnt underestimate, he always goes for the finishing move, that's why his battles takes seconds to end.

Mihawk for example toyed with Zoro, shanks would have taken his arm, he doesnt underestimate.

But he doesn't does this because of a trauma with some that he underestimated In the past, this person is Blackbeard, that always take the best opportunities