I get same message Which is bullshot since Class 9 Fearbone Arrows are the SAME trivial, and I can make those all day at skill 275 / 297 with trophy. Unless there's a book you need to scribe to learn the recipe, which is supposed to yield a different message if that's the case. Something like, "Something is wrong, perhaps if you learned something more..."
Maybe its because these are used in the Coldain Shawl 3.0 quest. You may need be 300 fletch or have the quest before you can do the combine. At any rate, doesn't look like you can skill up with this recipe. ChantressClio