Grace Kelly's 3 syllables (1 + 2) hit the Hollywood sweet spot.
Grace's 1 beat vs. Kelly's 2 create a natural cinematic snap.
Grace Kelly's softer consonants cost it screen presence.
Grace Kelly misses the alliteration hook that makes names stick.
Grace (5 letters) and Kelly (5) are balanced in length — clean on any poster or marquee.
Grace Kelly has mostly familiar phonemes with a few tricky patterns.
Grace Kelly has decent vowel richness, but stronger A and O sounds would lift it.