Wm sits next to 4 phonetic neighbors — William, Willem, and Wilhelm are the closest matches by sound. Most share Wm's English-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"resolute protector, will-helmet"
"red king"
"bright fame"
"Honor"
"worthy of love"
"called forth, gloriously summoned"
"council friend"
"princess, noblewoman"
"gentle, mild-mannered"
"sun, moon"
"gift of the ocean"
"hare's meadow, hare clearing"
"wealth, fortune, prosperity"
Similar sound: These names share phonetic patterns with Wm — 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 Wm.
Rhythm: Wm is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.