Marcos sits next to 4 phonetic neighbors — Marcus, Marco, and Marc are the closest matches by sound. Most share Marcos's Spanish-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"of Mars, consecrated to the god of war"
"of Mars, warrior"
"descendant of Jove (Jupiter)"
"altar/hearth of God"
"manly, brave"
"to conquer, to prevail"
"protector of mankind"
"man, warrior"
"home ruler"
"powerful ruler"
"dark-skinned, Moorish"
"man"
"rich spear, lucky warrior"
"of Mars, dedicated to Mars"
"river"
"son, born of"
"God's oath"
Similar sound: These names share phonetic patterns with Marcos — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Latin origins, giving them the same cultural heritage as Marcos.
Rhythm: Marcos is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.