Neilson sits next to 4 phonetic neighbors — Nelson, Neil, and Nielsen are the closest matches by sound. Most share Neilson's Scottish cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"son of Neil"
Similar sound: These names share phonetic patterns with Neilson — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Scottish patronymic origins, giving them the same cultural heritage as Neilson.
Rhythm: Neilson is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.