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"
"coastal land, border land"
"descent, gentle"
"youthful, downy-bearded (first beard)"
"God is salvation"
"settlement by the ash trees"
"son of Ed, son of the wealthy guardian"
"son of Garret, son of the spear bearer"
"wooded land"
"a large inland body of water"
"carrier of the anointed one"
"brave as a wild boar"
"variant of Cameron"
"raven's island"
"farmer, estate steward"
"hazel valley dweller"
"warrior, battle"
"Yahweh has given"
"son of the fiery one"
"glory-power"
"name of God"
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.