Sonnie sits next to 4 phonetic neighbors — Sunny, Sonny, and Donnie are the closest matches by sound. Most share Sonnie's English-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"sunny, bright, cheerful"
"peaceful will"
"settlement of Ella's people"
"the greatest one, supreme ruler"
"grandchild, descendant"
"independent, nonconformist"
"stone of Obsius"
"victorious people (via Kai + Nicholas blend)"
"rich in friends"
"corner, nook"
"hay valley, from the hay hill"
"variant of Kashton (Kash + ton)"
"possibly from Vashti, beautiful"
"wild boar hunter"
"dark one, little dark one"
"divine father"
"supplanter + hollow (blended from Jacob + Corey)"
"dear, beloved"
"sea, ocean"
"new, sky (nav element)"
"ox (original pictographic meaning)"
Similar sound: These names share phonetic patterns with Sonnie — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have English origins, giving them the same cultural heritage as Sonnie.
Rhythm: Sonnie is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.