Arlen sits next to 4 phonetic neighbors — Harlan, Marlon, and Darren are the closest matches by sound. Most share Arlen's Irish-rooted cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"pledge, oath"
"king, lord of the people"
"savior, one who saves"
"Chinese unicorn, bringer of good fortune"
"famous in battle"
"set apart, destined"
"descendant of Cinneide"
"free man, strong man"
"may God protect"
"Moorish, dark-complexioned"
"wise protector from the valley"
"high settlement or estate"
"rare, extraordinary"
"holy river"
"modest, shy"
"jaybird + euphonic suffix"
"dweller at the untilled ground"
"clay town, clay enclosure"
"ruler of the world"
"blue-purple dye, the color indigo"
"from the bailey (castle wall)"
Similar sound: These names share phonetic patterns with Arlen — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Irish Gaelic origins, giving them the same cultural heritage as Arlen.
Rhythm: Arlen is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.