If you are doing standard shapes like FG or HST, I'd say do it your way.
But I just bought and returned a $30 quilt pattern, which looked like it had regular old storm-at-sea kind of diamonds around a nice medallion, because I realized it called for Tri-recs PLUS Easy Angle AND Companion Angle. I resented having to buy the rulers so I wrote to the designer who very very very strongly recommends that the quilt be done using her method and those rulers in order to get the right end product.
Why don't you write to Quiltville and ask why you need all the rulers? she will know better than any of us.
Good luck!
PS I am a big fan of Debbie Tucker for Geese Wing Clipper. No waste, 4 at a time, no way to get wonky.