Gregory Peck's 4 syllables (3 + 1) hit the Hollywood sweet spot.
Gregory and Peck have a workable rhythm — close to the perfect punch.
Gregory Peck blends hard and soft consonants — decent presence, some softness.
Gregory Peck misses the alliteration hook that makes names stick.
Gregory (7 letters) and Peck (4) have a slight length mismatch, but it reads fine on screen.
Gregory Peck has mostly familiar phonemes with a few tricky patterns.
Gregory Peck has decent vowel richness, but stronger A and O sounds would lift it.