Monroe sits next to 3 phonetic neighbors — Monroe, Munroe, and Roe are the closest matches by sound. Most share Monroe's Scottish cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"from the mouth of the Roe river"
"luminous, shining"
"noble and famous"
"little king"
"associated with luxury and elegance"
"beginning, origin"
"immortality, eternal life (symbolic)"
"supplanter"
"winding river"
"noble elder"
"overseer, superintendent"
"Yahweh saves"
"all wise (from Norse Alviss)"
"resolute protector"
"worker in steel (occupational surname)"
"dark warrior"
"supplanter, one who follows at the heel"
"flax, flaxen-haired"
"valley dweller, from the valley"
"strip-shaped clearing in woodland"
"Hawaiian form of Matthew"
Similar sound: These names share phonetic patterns with Monroe — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Scottish Gaelic origins, giving them the same cultural heritage as Monroe.
Rhythm: Monroe is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.