I'm on PS4, l converted a zombie villager into a villager and l moved him far away from my village so he would not become influence by the jobs sites in my village. I had a Composter on me to make him become a farmer. The dice roll made him a Fletcher when he switch from zombie to a villager. Every time l place a composter next to him he would not become a farmer and l never traded with him when he became a Fletcher.