ha, I'm working on a herringbone path. I had used a similar geometry as to what you've got, but without that blue piece. Then I offset the tiling of the bricks until they lined up, and then rotated 45 degrees. It looks like in the iToo tut they already have the bricks modeled at the correct angle. I see that they assembled 2 pieces to be oriented into each other - but then separated them for reassembly in railclone. That's the step I missed!