Clarke sits next to 4 phonetic neighbors — Clark, Blake, and Drake are the closest matches by sound. Most share Clarke's English-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"clerk, scholar, scribe"
"son of Faelan (the little wolf)"
"God is gracious, son of Jack"
"short form of Christopher"
"that which one believes"
"free man"
"strong and steadfast"
"bold, brave"
"town in the forest (alternate etymology)"
"strong, healthy"
"one who runs (occupational surname)"
"hardworking; powerful"
"steward, estate manager"
"one who tells, narrator, counter of money"
"son of Rip (surname derivative)"
"uncertain; possibly Romani personal name with regional meaning"
"surname used as given name"
"at the ford (river crossing)"
"fashionable, manner of doing"
"heroic, kingly"
"gate keeper"
Similar sound: These names share phonetic patterns with Clarke — 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 Clarke.
Rhythm: Clarke is a 1-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.