Speros sits next to 3 phonetic neighbors — Spiro, Spyros, and Spyridon are the closest matches by sound. Most share Speros's Greek-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"associated with Saint Spyridon, miracle worker"
"sun"
"scholar"
"God is gracious"
"alder tree dweller"
"Dark one; descendant of Ciar"
"house of God (possible Bethel derivation)"
"army of the people"
"little man, young warrior"
"Ford by the windy place; a river crossing in a breezy location"
"field settlement"
"skilled metalworker"
Similar sound: These names share phonetic patterns with Speros — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Greek origins, giving them the same cultural heritage as Speros.
Rhythm: Speros is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.