Instead of putting the folk on the other folk, (they think of it as a gift) I put them on the grass, which just so happens to have another folk or two on it.
I did something similar before by placing a folk on an item, such as a stone, then placing other folk on top by right-clicking on the stone. A solution to fix this bug would be to prevent players/bots from placing folk on top of other objects (not including stone paths).