Shelby sits next to 3 phonetic neighbors — Shelby, Chelsey, and Selby are the closest matches by sound. Most share Shelby's English-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"willow farm, ledge estate"
"from the hill by the lake"
"rider, horseman, mounted warrior"
"god of war, justice, and single combat"
"modern invented compound name"
"swift, graceful (by association with deer)"
"place of the male deer"
"warrior people (Cree)"
"of the wood, forest"
"archer, bow-wielder"
"prince, little raven"
"invented by Sir Walter Scott, based on Old English Cerdic"
"God has remembered"
"son of the right hand"
"son of Dick, son of Richard"
"Carl's town or farm"
"enlightened, strong"
"wise power"
"of Shawn (Da prefix intensifier)"
"from Devon, the deep valley people"
Similar sound: These names share phonetic patterns with Shelby — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Old Norse origins, giving them the same cultural heritage as Shelby.
Rhythm: Shelby is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.