Berg sits next to 3 phonetic neighbors — Burke, Bjorg, and Borg are the closest matches by sound. Most share Berg's German-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"mountain, hill"
"one who pulls; stubborn"
"coined name combining Monte and Mario"
"narrow river"
"The wren bird; small, spirited songbird"
"Settlement by the rocks"
"land of the Indus River"
"from the River Bandon, white water"
Similar sound: These names share phonetic patterns with Berg — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Germanic origins, giving them the same cultural heritage as Berg.
Rhythm: Berg is a 1-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.