they use the 4 in a different way than they did this year. (Which was often hanging out in the corners, waiting for threes, and then driving off of them when the opportunity presented.)
He is definitely mainly a wing (sf, sg) and Then some 4, Imo. He can even play some point or at least bring the ball up - he did that a lot this year. He can play four of the five positions and against the right type of center, could even play against one.
But he's mainly a wing in my mind. I hope anyway. Even though he can be effective most anywhere, I see him most effective at the 3.
Wherever they play him, he has a great mid-range turnaround jumper that kind of looks like Kobe's that I hope they take advantage of.