Ac sits next to 4 phonetic neighbors — Ace, Casey, and AC are the closest matches by sound. Most share Ac's English-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"initials: various combinations (Andrew Charles, Anthony Cole, etc.)"
"Dealer in cloth and fabrics, cloth merchant"
"controlled release"
"birch meadow"
"weapon, mace bearer"
"pledged to God"
"divinely favored"
"undulating; like a wave"
"tax collector, rent farmer"
"hawk-like; stately"
"dearly loved"
"farm by the fen"
Similar sound: These names share phonetic patterns with Ac — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have American English origins, giving them the same cultural heritage as Ac.
Rhythm: Ac is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.