Morrison sits next to 5 phonetic neighbors — Harrison, Morrison, and Garrison are the closest matches by sound. Most share Morrison's English-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"son of Morris/Maurice"
"rejoice, be glad (via Gaius/Caio)"
"king"
"kermes-dyed, rich red"
"great oak, strength"
"of the highest power or authority"
"industrious ruler"
"beautiful mountain"
"pool near the elm tree"
"grey home, gravelly homestead"
"lion"
"calm, serene, protective"
"of the night"
"sun child, bright sun"
"army ruler (from Harold/Harald)"
"son of Guy"
"famous shouter, distinguished one"
"grey valley or settlement"
"God has been gracious"
"bright spirit, shining mind"
"earth (via Gaia connection)"
Similar sound: These names share phonetic patterns with Morrison — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have English origins, giving them the same cultural heritage as Morrison.
Rhythm: Morrison is a 3-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.