Coulter sits next to 4 phonetic neighbors — Colter, Colt, and Coulter are the closest matches by sound. Most share Coulter's Scottish cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"knife, cutting blade of a plow"
"desired, longed for"
"power of the sea"
"delight, paradise (as in Eden)"
"the white one, fair"
"one who heals"
"head, chief (as in penultimate)"
"from Hugh's meadow, Hucc's woodland clearing"
"crowned one"
"wealthy friend, divine wealth"
"small dwelling, storage chest"
"of uncertain meaning, possibly healer"
"dark, coal-black"
"gate keeper"
"ancient, enduring"
"peaceful territory, land of peace"
"dark warrior, little dark chieftain"
"great (via Chinese Quan)"
"building material, beam"
"from Courtenay (place in France)"
"son of Talmai, son of the furrows"
Similar sound: These names share phonetic patterns with Coulter — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Old English/Latin origins, giving them the same cultural heritage as Coulter.
Rhythm: Coulter is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.