Read a book about it years ago, might have been one of these
http://www.amazon.co.uk/s/ref=nb_sb_...e+kokoda+trail, and as far as I can remember one of the reasons the Japanese managed to push the Ausies in front of them while going uphill, in a single row, on a narrow trail, in mountainous jungle terrain, with supply lines getting longer and longer was the lack of heavy guns in the Ausie lines. The second reason is of course lack of coordination and planning.
viking