Griffith sits next to 3 phonetic neighbors — Griffin, Griffon, and Geoffrey are the closest matches by sound. Most share Griffith's Welsh cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"strong lord"
"one who wields prosperity"
"invented modern name, possibly blade-valley"
"servant, messenger"
"from Hesston (place name)"
"mythical bird of rebirth and immortality"
"Derived from Alfred, meaning counsel of elves"
"rope maker, bold counselor"
"dark one, little dark one"
"born of the ocean wave"
"place of elms"
"one who carves wood or stone"
"hay valley, from the hay hill"
"son of Hugh"
"Yahweh has remembered"
"wild boar hunter"
"from Sebastia"
"Yahweh is God"
"sunny, bright, cheerful"
"variant of Cassius, ancient Roman gens name"
Similar sound: These names share phonetic patterns with Griffith — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Welsh origins, giving them the same cultural heritage as Griffith.
Rhythm: Griffith is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.