Carsen sits next to 3 phonetic neighbors — Carson, Karsen, and Carsyn are the closest matches by sound. Most share Carsen's English-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"son of Carr, marsh dweller"
"without sorrow (Ashoka root)"
"one from the open heath"
"sea, ocean (alternate etymology)"
"oat field, oat harvest"
"bright meadow (invented combination)"
"manly, virile"
"of Mars, belonging to the war god"
"noble kind, noble type"
"God is gracious (via Irish Sean/John)"
"unique, one of a kind"
"rose pool, pretty lake"
"cinnamon, cassia tree"
"precious green stone"
"petite, feminine form of Charles"
"poetic, expressive of direct emotion (modern English sense)"
"city of light, Varanasi"
"lime tree meadow"
"fair hero"
"lake, waterfall"
"graceful, charming (implied by components)"
Similar sound: These names share phonetic patterns with Carsen — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Scottish/Old Norse origins, giving them the same cultural heritage as Carsen.
Rhythm: Carsen is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.