Rotha sits next to 4 phonetic neighbors — Rhoda, Rosa, and Rowena are the closest matches by sound. Most share Rotha's Germanic cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"Bright fame; from Germanic elements hrod (fame) and possibly related to rod (cleared land)"
"all true, entirely faithful"
"from Crete, the island"
"kola nut, sacred plant"
"pure"
"gift of God"
"resolute protector"
"excellent, outstanding"
"noble friend"
"from the island of Thera"
"Dweller at the marsh"
"bright, shining"
"joyful, merry, carefree"
"short form of Valerie or Valentina"
"breath, the living one"
Similar sound: These names share phonetic patterns with Rotha — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Germanic origins, giving them the same cultural heritage as Rotha.
Rhythm: Rotha is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.