Holstyn sits next to 4 phonetic neighbors — Austin, Holden, and Preston are the closest matches by sound. Most share Holstyn's German-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"dwellers in wooded hills"
"divine mother goddess (Irish)"
"valley dweller, from the meadow"
"place of meeting"
"eternal ruler"
"born of fire, handsome chief (via Kenneth/Cionaodha)"
"excellent, authentic (slang)"
"from the ash tree valley"
"well-born, noble"
"noble and ready, prepared for battle"
"new day, new light (interpreted)"
"golden one (from Latin aurum, gold)"
"pure strength"
"hat maker, cap maker"
"possibly derived from Jason (healer) via phonetic alteration"
"modern American coinage"
"from the Roman city of Lindum"
"strong, powerful (Roman association)"
"term of endearment for the firstborn or youngest son"
"estate of the fifth son"
"jaybird, joyful"
Similar sound: These names share phonetic patterns with Holstyn — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Old Saxon origins, giving them the same cultural heritage as Holstyn.
Rhythm: Holstyn is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.