Luther sits next to 3 phonetic neighbors — Luca, Luther, and Tucker are the closest matches by sound. Most share Luther's German-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"famous army, warrior people"
"cellar keeper, wine steward"
"friend, cherished person"
"flower"
"warrior, battle"
"messenger of God"
"man of the people"
"from Airelle (a place in Normandy, France)"
"to conquer, to win"
"strong, healthy"
"tailor, cutter of cloth"
"speed, power (modern association)"
"son of Ivar (yew warrior)"
"brotherly, genuine"
"from Kent, the English county"
"winding river"
"spring, fertility (earlier meaning)"
"Jehovah supports"
"messenger of God"
Similar sound: These names share phonetic patterns with Luther — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Old High German origins, giving them the same cultural heritage as Luther.
Rhythm: Luther is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.