yes very interesting there seems to be no real pattern to where they go, obviously there is a reason to why I am sure one of the guys here will enlighten us?
Many types of nails are used .. Nails, bolts, bolts with pin, harpoons, etc ... There is no aesthetic pattern to put them, but they were put for effectiveness to strengthen the structure. In Spanish galleons almost all these pieces are made of metal. Almost no wooden bars are used