Stephan sits next to 4 phonetic neighbors — Stefan, Steven, and Stephen are the closest matches by sound. Most share Stephan's German-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"crown, wreath"
"harp player, one who plays the harp"
"son of Ed, son of the wealthy guardian"
"follower of Calvin (in Protestant tradition)"
"glory-power"
"beloved youngest son"
"handsome, beautiful"
"one who illuminates, enlightener"
"elm grove"
"lion strength"
"red-haired, little redhead"
"father of peace"
"from the high woodland clearing"
"the greatest"
"fallow land, meadowland"
"the fifth"
"staff bearer, wand wielder"
"cloud"
"peace power"
"wanderer (from Scotti people's migrations)"
"modern creative name construction"
Similar sound: These names share phonetic patterns with Stephan — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Greek origins, giving them the same cultural heritage as Stephan.
Rhythm: Stephan is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.