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"
"great, venerable, majestic"
"one who helps"
"good place"
"long narrow hill"
"may God protect"
"laughter"
"of Mount Carmel"
"battle, warrior spirit"
"great brightness, sea circle"
"large gun, artillery piece"
"one who brings news"
"short form of Benjamin: son of the right hand"
"son of Ridge"
"of the Julian family"
"foot soldier"
"wise protector"
"fair, white, bright"
"crooked valley"
"people's power"
"immortal, divine"
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.