Will sits next to 4 phonetic neighbors — Bill, Phil, and Gil are the closest matches by sound. Most share Will's English-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"resolute protector"
"peninsula, point of land"
"son of the red warrior"
"lowlands"
"God is gracious"
"from the western direction"
"noble and famous"
"from the Adriatic region"
"free one"
"possession, acquisition"
"my messenger, my angel"
"God enlightens, He shines"
"son of Javan, modern invention"
"dark, swarthy"
"red river settlement"
"land of Eoghan (Owen)"
"god-helmet"
"son of Jack"
"victory of the people"
"from the heath"
"spear ruler"
Similar sound: These names share phonetic patterns with Will — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Germanic origins, giving them the same cultural heritage as Will.
Rhythm: Will is a 1-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.