Gordon sits next to 3 phonetic neighbors — Jordan, Cordon, and Gordie are the closest matches by sound. Most share Gordon's Scottish cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"great fort, spacious hill"
"acquired, possessed"
"near the holly trees"
"beautiful, handsome"
"place by the forest"
"foreigner, Welshman (Celtic speaker)"
"son of the gray-haired one"
"shield wolf, protector"
"son of the south"
"possession, acquisition"
"coal farm"
"he who causes distress"
"roof maker"
"Caesar (imperial title)"
"son of the brown-haired one"
"one who lives near the fens or marshes"
"skill acquired through experience"
"noble power, powerful ruler"
"the younger one"
"watchful, vigilant (via Casey)"
"father of peace"
Similar sound: These names share phonetic patterns with Gordon — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Scottish Gaelic/Brittonic origins, giving them the same cultural heritage as Gordon.
Rhythm: Gordon is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.