Alvira sits next to 3 phonetic neighbors — Elvira, Alvira, and Almira are the closest matches by sound. Most share Alvira's Spanish-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"all true, completely true"
"wonderful, to be admired"
"battle horn"
"blooming, fresh, green"
"gentle, mild"
"of the Balbinus clan"
"numbness, the narcissus plant"
"champion"
"bright, famous"
"flowing, moving freely"
"of Rome, Roman woman"
"variant of Cinda/Cindy"
"prosperous friend"
"from Leicester; possibly heavenly"
"settlement of the Britons"
"meadow on a ledge"
Similar sound: These names share phonetic patterns with Alvira — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Visigothic Germanic al + wer origins, giving them the same cultural heritage as Alvira.
Rhythm: Alvira is a 3-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.