Tong sits next to 4 phonetic neighbors — Tang, Long, and Kong are the closest matches by sound. Most share Tong's Chinese cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"paulownia tree, nobility (桐)"
"noble, bright"
"market trader, merchant"
"broad fortified settlement"
"valley peace; combination of Del (valley) and Fred (peaceful ruler)"
"Sea of bitterness"
"blessed ring, white circle (Welsh derivation)"
"Free man; from Germanic karl meaning man or free man, via Old Frenc..."
"ever powerful"
"reborn, born again"
"powerful warrior"
Similar sound: These names share phonetic patterns with Tong — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Chinese origins, giving them the same cultural heritage as Tong.
Rhythm: Tong is a 1-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.