Harlen sits next to 3 phonetic neighbors — Harlan, Harley, and Darlen are the closest matches by sound. Most share Harlen's English-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"rocky land, gray land"
"divine power, God's rule"
"highlands, uplands"
"red-haired, from the russet one"
"Dack's settlement"
"supported by Yahweh"
"high ground, elevated place"
"son of the famous ruler"
"my people"
"anglicization of Welsh Llwyd"
"third son"
"gift of Yahweh"
"creative spelling of Rustin"
"God is gracious"
"keeper of enclosed parkland"
"rich, powerful ruler"
"to hunt, to chase"
"the shining one"
"cooked rice, meal"
"strength and help of God (combined from Ezra and Azariah)"
Similar sound: These names share phonetic patterns with Harlen — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Old English har + land origins, giving them the same cultural heritage as Harlen.
Rhythm: Harlen is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.