Allen sits next to 4 phonetic neighbors — Alan, Allan, and Alain are the closest matches by sound. Most share Allen's English-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"handsome, cheerful"
"may God protect"
"God has consoled"
"supplanter's son"
"valley settlement"
"crow, dark bird"
"maker of cases or boxes"
"honest, steadfast"
"God strengthens, Yahweh is my strength"
"little dark one"
"bright in mind and spirit"
"foot soldier"
"son of the fair one"
"narrow strait"
"western enclosure"
"strong, virtuous, honorable"
"from the south village"
"beautiful friend, fair friend"
"group, band, team"
"white/pale (from Cas people)"
Similar sound: These names share phonetic patterns with Allen — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Celtic origins, giving them the same cultural heritage as Allen.
Rhythm: Allen is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.