Des sits next to 3 phonetic neighbors — Dez, Des, and Wes are the closest matches by sound. Most share Des's Irish-rooted cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"from South Munster (southern Ireland)"
"from the white meadow"
"Little fire (as variant of Aidan)"
"sudden dash or rush"
"from the hill settlement, dweller by the downs"
"highest point, peak, summit"
Similar sound: These names share phonetic patterns with Des — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Irish origins, giving them the same cultural heritage as Des.
Rhythm: Des is a 1-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.