So I was making a villager breeder with 20+ beds, an open roof, and a 10x10 area. I give the just cleric and armorer a stack of bread. They show the hearts, and occasionally the angry particles, but never ever is there a child that spawns. Maybe it's because the armor villager is still assigned to the blast furnace on the home village? It could be, I have the chunk loaded in. Take a look at this behavior and tweak it so villagers become unassigned when they are a certain distance from their workplace. 

Edit: Destroyed native workplaces and beds. Some villagers took on the nearest professions, some didn't. Some of them still won't sleep at night, and won't breed.