I know this is rank heresy, but I play with extremely short nails. They barely reach the tips of my fingers, and they're filed to match the contour of the fingertip.
Back when I started classical guitar (many, many years ago), there was not so much discussion about nail shape. In fact, as I recall, the nail shape that was taught (or at least inferred) followed my current practice, albeit the "proper" length was somewhat longer than I use now. When I left guitar to concentrate on harp (Medieval and wire-strung technique: using nails still, but on both hands), I shortened my nails, particularly when I got a regular gig and a broken nail would be a major disaster. In fact, it was nail breakage that caused me to give up the long nails and play with my very short nails.
I should mention that, regarding wire-strung harp technique, the current orthodoxy specifies *long* nails, filed slantwise: much the same as I'm seeing in some of the nail discussions about classical guitar. Honestly, I mostly don't care for the sound produced by these harpers, and I shudder to think what their nail-upkeep routine must be.
But I played wire-strung harp with short nails for years and never had much of a problem either with length or with tone.
I don't really feel that, even with my very short nails, I'm having much of a tonal problem with classical guitar. (I accept the fact that others may disagree.) One of the advantages of short nails is that breakage becomes less of a problem. In fact, the only time I really cause damage to my nails is when I'm working the heavy bag: my bag gloves compress the outside (pinky finger) corner of my index fingernail and cause a whitened stress fracture. (I just file off the damaged part.) Another advantage is that I don't have as many problems executing daily tasks...such as the typing I'm doing now. In fact, I can tell when my nails need shortening when I start to feel them impact on the bezel surrounding my keyboard keys.
So maybe I'm wrong, but this nail length appears to work for me.
I mention all of this for the sake of those who, like me, have problems with "tracing paper" and or hooked nails.