In the real logging world especially in the far west where trees grow that large(hundreds of years) true lumberjacks wouldn't be fazed. They first cut a slot to fit a piece of board so they have a flat reasonably stable platform to start swinging that very sharp axe. In no time the chips are flying, once deep enough, they switch to the otherside to complete the cut. Slightly higher. At this point, the tree falls to the side they made the first cut.
Ok your trimmers, come do your job so I can go to the next BIG tree and get going on it. Then somebody better bring me a drink and some grub.
I have seen lumberjacks competing with each other. Great fun to watch. It is absolutely amazing to see what they can accomplish in a very short time.
I am pleased to see you posting these interesting views Shamus my friend. They are just great.