Wilhelm sits next to 3 phonetic neighbors — William, Willem, and Vilhelm are the closest matches by sound. Most share Wilhelm's German-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"resolute protector"
"gift of God"
"shining from the north"
"from the hedged land"
"divine mother goddess (Irish)"
"of Julius, belonging to the Julian family"
"fortified stronghold"
"Trey's town, three's farm"
"sky (variant of Kai)"
"descendant of the earl"
"he will laugh, laughter"
"born at daylight"
"he will laugh, laughter, one who laughs"
"renowned power"
"faithful as a dog, devoted"
"day"
"cutting edge of a sword or tool"
"worthy, of value"
"large settlement, big homestead"
Similar sound: These names share phonetic patterns with Wilhelm — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Old High German origins, giving them the same cultural heritage as Wilhelm.
Rhythm: Wilhelm is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.