Eldren sits next to 3 phonetic neighbors — Eldon, Aldric, and Eldritch are the closest matches by sound. Most share Eldren's English-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"old, wise ruler"
"nobleman, pledge"
"house of God (possible Bethel derivation)"
"The great; the large"
"24-hour period"
"dark river, dark stream"
"from the alder grove"
"the strait, narrow waterway"
"raven"
"olive tree; symbol of peace and wisdom"
"loving, affectionate (if from Philemon)"
"sunray, shining light"
"Ford by the windy place; a river crossing in a breezy location"
"field settlement"
Similar sound: These names share phonetic patterns with Eldren — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Old English origins, giving them the same cultural heritage as Eldren.
Rhythm: Eldren is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.