Stanley sits next to 3 phonetic neighbors — Hanley, Manley, and Brantley are the closest matches by sound. Most share Stanley's English-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"stony meadow"
"he who holds firm the good"
"from the fen, marshland dweller"
"large gun, artillery piece"
"wise protector"
"tournament fighter"
"noble friend, elf friend"
"in him there is strength"
"fifth"
"panache, flair (as in 'cut a dash')"
"noble, handsome"
"none compares to God"
"peace, gentleness"
"land of lakes"
"remedy, cure (folk etymology)"
"lisping"
"bold and modern (cultural meaning)"
"exalted father"
"descendant of Madan (little dog)"
"courageous heart"
"God is gracious"
Similar sound: These names share phonetic patterns with Stanley — 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 Stanley.
Rhythm: Stanley is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.