Otto sits next to 3 phonetic neighbors — Otis, Arlo, and Hugo are the closest matches by sound. Most share Otto's German-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"wealth, fortune, prosperity"
"imperial title, ruler"
"from the coal settlement or dark town"
"little warrior, war-associated"
"one who lives near a riverbank"
"round barrel, lump"
"son of the young warrior"
"park keeper"
"master, conqueror"
"universal, whole"
"famous warrior"
"good fortune, luck"
"descendant of the dark one"
"from Santino (little saint)"
"savior"
"free, liberated"
"flourishing"
"oak tree meadow"
"bright in mind and spirit"
"clearing of coarse grass"
Similar sound: These names share phonetic patterns with Otto — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Old High German origins, giving them the same cultural heritage as Otto.
Rhythm: Otto is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.