Jim, what you say makes sense to me. I'm guessing the 6x6 frame is held together by lag screws or bolts. I built an 8'x8'x8' gazebo with 4x4 posts and notched out a place on top for some 4x6 beams. After this, the post was narrowed considerably, probably down to 2x2 at that point. But it had 4x4 braces screwed to the timbers, and it is still standing.
