Arthur sits next to 3 phonetic neighbors — Archer, Arturo, and Artur are the closest matches by sound. Most share Arthur's English-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"bear, bear-like strength"
"upright, fair"
"great, venerable, majestic"
"brave boar"
"handsome, beautiful"
"healer, to heal"
"From Old French 'macon' meaning one who works with stone; originall..."
"son of the hood/hooded man"
"of Mars, warlike"
"flowing body of water"
"may God strengthen him"
"the river Jordan"
"from Sebastia, venerable"
"Yahweh is salvation"
"little red-haired one"
"son of Jack"
"he gave, gift from God"
"to prevail, to win"
"western farmstead, western settlement"
"little fire"
"master, conqueror"
Similar sound: These names share phonetic patterns with Arthur — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Brythonic Celtic origins, giving them the same cultural heritage as Arthur.
Rhythm: Arthur is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.