Irvin sits next to 4 phonetic neighbors — Irving, Ervin, and Erwin are the closest matches by sound. Most share Irvin's Scottish cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"green/fresh river"
"creative spelling of Rustin"
"falling, rhythmic beat"
"ocean person"
"God is gracious"
"meadow of the gods"
"chosen deliverer, consecrated leader"
"one who sets free"
"fair warrior"
"son of Carr, from the marsh"
"little fire"
"ancient, enduring"
"beautiful valley"
"oak meadow, clearing in the oaks"
"from Airelle (a place in Normandy)"
"to reap, harvest"
"meadow town"
"short for Indiana (land of Indians)"
"son of Adam"
"firebrand, burning torch"
"white, fair-complexioned"
Similar sound: These names share phonetic patterns with Irvin — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Brittonic/Celtic origins, giving them the same cultural heritage as Irvin.
Rhythm: Irvin is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.