Boston sits next to 3 phonetic neighbors — Austin, Benson, and Preston are the closest matches by sound. Most share Boston's English-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"Botolph's town, market town"
"southern settlement, south farm"
"candle maker or seller"
"spear rule"
"ruler's counsel"
"son of Jeffrey, son of God's peace"
"fearless, not cowardly"
"brave warrior (later folk etymology)"
"made by God"
"son of James"
"narrow water crossing"
"hollow, ravine"
"the ram"
"famous spear"
"estate of the fifth son"
"nobleman, duke"
"lisping"
"ever awake"
"sea-born, born of the sea"
"great surrounding sea"
"Lord (via Kyrie element)"
Similar sound: These names share phonetic patterns with Boston — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Old English origins, giving them the same cultural heritage as Boston.
Rhythm: Boston is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.