In reply to Flinticus:
I think parts of the north ridge of Tryfan (particularly higher up on the final approach to the far north summit) are graded 2 by some guides. However they are avoidable by the easiest route.
However, you probably have a point. One of my favourite North Wales scrambles is the Clogwyn y Person arete up onto Crib y Ddisgl, which is graded 2/3 like Curved Ridge. I can assure you it is a fair bit harder and more exposed than Curved Ridge, and has a couple of awkward thrutchy moves up a chimney.
I was tempted to say that Scottish scrambling grades are on the easier side, but I am aware that some of the routes on the N and E faces of Stob Coire nam Beith on Bidean have quite a fearsome reputation (not tried them yet), so it probably isn't as simple as that.
Post edited at 12:21