Sandra sits next to 4 phonetic neighbors — Cassandra, Sondra, and Saundra are the closest matches by sound. Most share Sandra's English-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"defender of men"
"bitter sea, wished-for child"
"dark, black"
"new beginning"
"child of heaven"
"helper, protector"
"Yahweh is God"
"dedicated to Mars"
"pretty, beautiful"
"short form of Emma or Emilia"
"mine, of the Lord"
"noble elf ruler"
"famous warrior (heil + wīg)"
"crystal clear"
"strong, vigorous"
"the jade gemstone"
"to strive, to rival, to excel"
"night angel"
"seaweed (edible)"
"royal daughter, daughter of a king"
"dyer of red cloth"
Similar sound: These names share phonetic patterns with Sandra — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Greek via Italian origins, giving them the same cultural heritage as Sandra.
Rhythm: Sandra is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.