Robin Williams's 4 syllables (2 + 2) hit the Hollywood sweet spot.
Robin's 2 beats vs. Williams's 2 create a natural cinematic snap.
Robin Williams's softer consonants cost it screen presence.
Robin Williams misses the alliteration hook that makes names stick.
Robin (5 letters) and Williams (8) have a slight length mismatch, but it reads fine on screen.
Robin Williams has mostly familiar phonemes with a few tricky patterns.
Robin Williams's open vowels roll off the tongue — warm and screen-ready.