Duncan got a mid range jumper to prolong his career, that thing is now money and keeps guy up on him to the point where he can drive as well. If he was still in the post the whole game pushing and banging against bulkier players his knees would be shot.
But again we are not looking at whether we have Tiago or Al, we would have both as Utah does not want a big man back when they are trading because they want their young bigs to play more. They will be looking for 3 pt help and some ball handling so if it happened we would have TD and Al starting with Tiago on first drop.
........ And World Peace