I match drilled all the holes between rudder skin and the rudder skeleton. I also final drilled the holes between both skins and the trailing edge.
There was only one arbitrary thing involved in this step. The instructions called for drilling perpendicular to the chordline of the rudder - not the skin. I did the best I could possible do, but as I've learned - there's always a point a few steps later where the truth comes out and you know if you've done it correctly or not.
