Hasan sits next to 4 phonetic neighbors — Hassan, Jason, and Mason are the closest matches by sound. Most share Hasan's Arabic-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"excellent, virtuous"
"archer, one who shoots"
"attainer, one who gains"
"lush, well-watered, abundant"
"sword"
"immortal, eternal"
"moistening, life-giving water"
"generosity, nobility"
"little ancient one"
"the Most Merciful (divine attribute)"
"most merciful, most compassionate"
"of Armenian land, Armenian man"
"peace, security"
"perfect, unblemished"
"certificate of authenticity"
"friendliness, sociability"
"Yahweh remembers"
"luck, fortune (from Gad)"
"land desiccated from water"
Similar sound: These names share phonetic patterns with Hasan — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Arabic origins, giving them the same cultural heritage as Hasan.
Rhythm: Hasan is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.