Arnold sits next to 4 phonetic neighbors — Harold, Roland, and Donald are the closest matches by sound. Most share Arnold's German-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"eagle power, eagle ruler"
"swift projectile, arrow"
"from the hazel tree settlement"
"son of Rand, son of the shield-wolf"
"the brave ones, the warriors"
"wanderer (from Scotti people's migrations)"
"shelter, protection"
"one who shines, illuminates"
"narrow strait"
"modern invented name"
"one who moves with speed"
"disciple of the dove"
"from the, of the family"
"resolute fame, desired renown"
"variant of Cameron"
"wooded land"
"modern coined name, variant of Kyson"
"world ruler"
"descendant of Grey"
"blue-purple dye, the color indigo"
"peaceful ruler"
Similar sound: These names share phonetic patterns with Arnold — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Germanic origins, giving them the same cultural heritage as Arnold.
Rhythm: Arnold is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.