Also, there's a discussion to be had about propping one of your better offensive rebounders at the three point line.
There is -- and I am on record as saying I don't like Sully take threes for this exact reason -- however a bricked three tends to be a long rebound anyway.
It also is more complicated than that.
Kevin Love averages 3.5 offensive rebounds per game, and also shoots 6 threes a game. Sully still averages 2 offensive rebounds per game in just about 20 minutes, which is essentially the same rate he was at last year.
It is a missed conception that rebounders need to be playing close to the hoop to grab offensive rebounders. In fact, the best offensive rebounders (other than the few rare guys who just are so big they grab everything, like say, Andrew Bynum), are guys who are mobile and keep moving. And that is what Sully (and Love) do when they play on the perimeter. They don't stand in one place, waiting for the ball. They are in constant motion, and can see the ball going up and get in position.
This is also why Rondo is such a good offensive rebounder. He doesn't play under the basket. He just reads the play, and from the perimeter, he is able to read the shots, and see where the rebound is going to go.
Sully is at his best, when he uses the whole court. He does damage in the low-post, high-post, and on the perimeter. And he is constantly moving, setting picks, and moving the ball as part of the offense. He disappears when he stays in one place.
So, I think having him add this as part of his game, and keep him moving just helps him stay active, and often gives him good reads on offensive rebounds.