Marcellus sits next to 4 phonetic neighbors — Marcus, Marcel, and Maximus are the closest matches by sound. Most share Marcellus's English-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"little warrior, young Mars"
"loyal"
"high guardian, high watchman"
"the greatest, the largest"
"of Mars, warlike"
"sandalwood tree"
"protector of men"
"son of the cloud"
"God has given"
"father of light"
"speckled, freckled"
"ruler of all, universal ruler"
"queen's settlement"
"anointed one"
"Gomeric's mountain, power mountain"
"ruler, sovereign"
"to rejoice, joyful"
"venerable, revered"
"bounty, kindly, beloved"
"woodland"
Similar sound: These names share phonetic patterns with Marcellus — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Latin origins, giving them the same cultural heritage as Marcellus.
Rhythm: Marcellus is a 3-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.