Harlan sits next to 4 phonetic neighbors — Harlen, Harley, and Carlan are the closest matches by sound. Most share Harlan's English-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"rocky land, stony ground"
"old friend, noble friend"
"spear strength, brave with the spear"
"mighty power, ruler"
"one who brings news"
"of Dionysos, god of wine"
"good place"
"to heal"
"God has established (via Jachai root)"
"handsome, beautiful"
"dark man's settlement, coal-black farm"
"Yahweh has strengthened"
"younger, the son"
"mind, intellect, spirit"
"one who serves"
"fallow land, uncultivated land"
"wanderer, Gaelic speaker"
"illustrious through nobility"
"father figure, patriarch"
"pledge, security deposit"
"lover of horses"
Similar sound: These names share phonetic patterns with Harlan — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Old English origins, giving them the same cultural heritage as Harlan.
Rhythm: Harlan is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.