Wellington sits next to 3 phonetic neighbors — Ellington, Pennington, and Harrington are the closest matches by sound. Most share Wellington's English-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"from the wealthy estate, prosperous settlement"
"the smallest unit of matter"
"little fire, flame"
"gift of God"
"farm on a hill, settlement by a mound"
"evergreen juniper tree"
"glorious protector (as diminutive of Branislav)"
"short form of Bogoris (divine gift)"
"God raises up"
"fashionable, manner of doing"
"healthy, wise"
"red, ruddy"
"to hide"
"volcanic tuff (durable rock)"
"oak lake"
"dark one, little dark-haired one"
"warlike, fighter (from Thracius)"
"divine, holy"
"miracle of God"
"clerk, scholar, scribe"
"uncertain; possibly Romani personal name with regional meaning"
Similar sound: These names share phonetic patterns with Wellington — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Old English 'Weola-ingtun' origins, giving them the same cultural heritage as Wellington.
Rhythm: Wellington is a 4-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.