Jack sits next to 3 phonetic neighbors — Jake, Zack, and Max are the closest matches by sound. Most share Jack's English-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"supplanter"
"One who transports goods by cart; cart driver"
"from Hadria, of the Adriatic"
"rock, stone"
"lion"
"titan who bore the heavens"
"anointed one"
"gift of God"
"laughter, joy"
"healer"
"holder of the heel"
"fire of the Lord"
"bear, bear-like strength"
"strong as a lion"
"gift of Yahweh"
"wealthy"
"praised, thankful"
"strife, quarrel"
"man from Lucania"
Similar sound: These names share phonetic patterns with Jack — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Hebrew origins, giving them the same cultural heritage as Jack.
Rhythm: Jack is a 1-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.