Sean sits next to 4 phonetic neighbors — Shawn, Shane, and Shaun are the closest matches by sound. Most share Sean's Irish-rooted cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"God is gracious"
"peace, submission to God"
"world-encircling waters"
"strong man, warrior"
"valley settlement"
"battle (possible Irish Gaelic root)"
"mind, spirit, heart"
"delight, luxury"
"great, venerable, majestic"
"Beauty, grace"
"one who is learned"
"from Brix (place name)"
"elder, more important"
"renowned in battle"
"favored by the gods"
"one who transports goods by cart"
"God has heard"
"from Lucania"
"clearing among oaks"
Similar sound: These names share phonetic patterns with Sean — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Hebrew via Irish origins, giving them the same cultural heritage as Sean.
Rhythm: Sean is a 1-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.