Sagan sits next to 5 phonetic neighbors — Logan, Reagan, and Caigan are the closest matches by sound. Most share Sagan's Polish-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"from Żagań (city in Poland)"
"victory of the people (via Nicasen interpretation)"
"one who has achieved his goal (from Siddharth)"
"slender, narrow one"
"gift, good-natured"
"vivid, alive"
"home ruler"
"the fast one, arrow"
"from Devon, poet"
"modern American creation with roots in Keon (God is gracious)"
"lion"
"one who rides, horse rider"
"from the east, eastern settlement"
"from the ash tree dell"
"fidelity, eternity"
"son of the fair hero"
"young wolf, wolf cub"
"short form of James, via Jacob from Ya'aqov"
"slender, powerful"
"God is gracious"
"strong, powerful"
Similar sound: These names share phonetic patterns with Sagan — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Polish/Silesian origins, giving them the same cultural heritage as Sagan.
Rhythm: Sagan is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.