Garrison sits next to 4 phonetic neighbors — Harrison, Garrison, and Garson are the closest matches by sound. Most share Garrison's English-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"son of Garret, son of the spear bearer"
"dove"
"moon"
"he enlightens, God enlightens"
"variant of Drew, meaning manly/strong"
"high place, hill top"
"moonlit, of the moon"
"YHWH saves"
"warrior, strong fighter"
"son of Kenneth / son of Coinneach"
"from the hazel tree settlement"
"crown, wreath"
"uncertain, possibly warrior spirit"
"rim of a shield"
"victors garland"
"canal worker, church official"
"steep hill meadow"
"green river, fresh water"
"admirable, hawk-like"
"peaceful ruler"
"wealthy and powerful"
Similar sound: These names share phonetic patterns with Garrison — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Germanic/English origins, giving them the same cultural heritage as Garrison.
Rhythm: Garrison is a 3-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.