Dallin sits next to 3 phonetic neighbors — Dillon, Dylan, and Dalton are the closest matches by sound. Most share Dallin's Welsh cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"from the valley"
"son of David, son of the beloved"
"initials — varies by family"
"world ruler"
"keen ruler, bold king"
"spike, pointed"
"little fire (via Aiden root)"
"modern elaboration of Darren"
"acquired, possession"
"absence of conflict, wholeness"
"cat"
"clean, righteous"
"father of peace"
"lord, sovereign"
"associated with Al-Khidr, the immortal guide"
"God is my illumination"
"impulsive, wrathful"
"young, youthful"
"the cleansing one, the rinser"
"lake dweller"
"trust, reliance"
Similar sound: These names share phonetic patterns with Dallin — 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 Dallin.
Rhythm: Dallin is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.