Shamsuddin sits next to 3 phonetic neighbors — Saifuddin, Kamaluddin, and Jamaluddin are the closest matches by sound. Most share Shamsuddin's Arabic-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"sun of the faith, sun of religion"
"a sense of the familiar"
"raging flow"
"wholehearted, faithful, devoted"
"great, majestic"
"light breeze, gentle wind"
"stream, rivulet, small river"
"Virtuous, worthy, able"
"devoted to Demeter, goddess of harvest"
Similar sound: These names share phonetic patterns with Shamsuddin — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Arabic origins, giving them the same cultural heritage as Shamsuddin.
Rhythm: Shamsuddin is a 4-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.