Leif sits next to 2 phonetic neighbors — Leaf and Lafe are the closest matches by sound. Most share Leif's Scandinavian cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"heir, descendant, beloved"
"father of peace"
"triumphant champion"
"warrior lion"
"leader, commander (variant interpretation)"
"the twin"
"great"
"council friend"
"ruler of the army (Scandinavian form)"
"rest, comfort (when used as variant of Noah)"
"free man"
"bringer of treasure (gift-bearer)"
"passionate, earnest"
"wise counselor"
"messenger"
"God is gracious"
"brook, running water"
Similar sound: These names share phonetic patterns with Leif — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Old Norse origins, giving them the same cultural heritage as Leif.
Rhythm: Leif is a 1-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.