Edwin sits next to 3 phonetic neighbors — Edmund, Edward, and Edwyn are the closest matches by sound. Most share Edwin's English-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"rich friend, prosperous friend"
"handsome, beautiful"
"opportunity, happenstance"
"river that swallows all rivers"
"noble Roman citizen"
"arrow maker"
"little fawn"
"royal son; prince"
"place of elms"
"son of Kay"
"keeper of horses, horse servant"
"peaceful, gentle as a dove"
"brave in battle"
"to tame, to subdue"
"kingly, of royal blood"
"birth, nativity"
"keeper of the pantry"
"beauty, adornment, grace"
"manly, brave"
"invented name, possibly evoking sky"
"Yahweh is merciful"
Similar sound: These names share phonetic patterns with Edwin — 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 Edwin.
Rhythm: Edwin is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.