Joan sits next to 3 phonetic neighbors — John, Juan, and Jon are the closest matches by sound. Most share Joan's Spanish-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"God is gracious"
"wealthy guardian"
"ruler of the army (Scandinavian form)"
"modern invented name"
"faithful, loyal, trustworthy"
"may God protect"
"from Scotland, a Scotsman"
"the greatest, the largest"
"God has helped"
"Yahweh has created"
"strength, permanence"
"God enlightens, he shines"
"bright"
"son of the right hand"
"from Mauritania"
"stony meadow"
"eternal, perpetual"
"divine justice"
"dark, dark-haired"
"to increase, augur"
"power of the tribe"
Similar sound: These names share phonetic patterns with Joan — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Hebrew origins, giving them the same cultural heritage as Joan.
Rhythm: Joan is a 1-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.