In their diagrams it looks like some of the logs still have flattened tops and bottoms for some of the designs. Doesn’t the average thickness of the wall depend

In their diagrams it looks like some of the logs still have flattened tops and bottoms for some of the designs. Doesn’t the average thickness of the wall depend on the flatness of the logs? (If they are perfectly round geometry-universe cylinders, I guess they will only be touching along a one-dimensional line).