Jacaerys sits next to 4 phonetic neighbors — Viserys, Zacarias, and Jace are the closest matches by sound. Most share Jacaerys's English-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"royal dynastic heir (constructed language)"
"supplanter, held by the heel"
"of Tyre, the ancient city"
"named for gold prospector Joe Juneau"
"from Airelle (place in Normandy, France)"
"healer, one who heals"
"ancient, enduring"
"from Brittany, land of the Britons"
"broad stone settlement"
"one who bakes bread"
"settlement by the brushwood"
"guardian dragon of the golden apples"
"new house"
"one who mows or cuts"
"God is gracious"
"of noble birth"
"pledge, oath, measure"
"son of Hugh"
"little king, kingly"
Similar sound: These names share phonetic patterns with Jacaerys — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have High Valyrian (fictional) origins, giving them the same cultural heritage as Jacaerys.
Rhythm: Jacaerys is a 4-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.