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)"
"outlaw, pursued one"
"slender, narrow one"
"good man"
"strong lord"
"navigator, guide"
"hollow stone, hollow hill"
"creative respelling of Zion (highest point, monument)"
"spirited, broad"
"queen, counsel"
"of Mars, warrior (Marius element)"
"world ruler, ruler of the world"
"light, illumination"
"one who rides, horse rider"
"eternal ruler"
"energy, spirit, vigor"
"fiery one"
"blackbird"
"lover of horses"
"sea, ocean (from the Kai element)"
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.