I think in this case its not a 10 degree down angle thing it's the fact you take the sharpest file there is, use all of your strength, and the file just scrapes over the tooth removing zero metal. It's harder then the file.
Then the next tooth you remove an 1/8th" in two strokes because its so soft.
I would two of each teeth per loop....That's when it was 11.99 at Baileys in 2003 ish.
Even Baileys realised they had a problem,kept the chassis probably because it was cheaper and purchased decent teeth.
I'm just guessing, but something positive changed because Baileys chain is pretty good. I was told by someone at that company about the Oregon teeth.