Harmoni sits next to 3 phonetic neighbors — Harmony, Hermione, and Armony are the closest matches by sound. Most share Harmoni's English-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"agreement, concord, fitting together"
"daughter of the sea"
"cushion, pillow"
"defender of men"
"beautiful friend"
"graceful movement"
"my God is the Lord (via Hebrew Elijah)"
"day of rest and worship"
"precious gem"
"lake (suffix)"
"lily of grace"
"noble, nobility"
"modern invented name"
"white island"
"elf ruler with feminine suffix"
"protector, she who defends"
"noble, high meadow"
"ruler of the elves"
"youthful, downy-bearded"
"holy, blessed"
Similar sound: These names share phonetic patterns with Harmoni — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Greek origins, giving them the same cultural heritage as Harmoni.
Rhythm: Harmoni is a 3-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.