Sheppard sits next to 4 phonetic neighbors — Shepherd, Shepard, and Shephard are the closest matches by sound. Most share Sheppard's English-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"herder of sheep, shepherd"
"bold, brave"
"the smallest unit of matter"
"talon, claw of a bird of prey"
"of royal lineage, kingly"
"falcon keeper, falconer"
"defender of men, protector of the people"
"town in the forest (alternate etymology)"
"brave as a bear, bear strength"
"from Hadria, near the Adriatic"
"harmony, one"
"short form of Christopher"
"dark one, descendant of the dark one"
"my gift"
"moonlight; of the moon"
"oak lake"
"temple of the soul of Ptah"
"champion, winner"
"born of yew tree"
"warrior, gift of God"
"land near the court or manor"
Similar sound: These names share phonetic patterns with Sheppard — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Old English origins, giving them the same cultural heritage as Sheppard.
Rhythm: Sheppard is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.