Villages that spawn with small houses always spawns farmer villagers (brown coated villagers). Also in one of the houses they spawn more than they should. For example: in the butchers' house they spawn 3 villagers instead of 2. The number of farmer villagers that farm during the day cause a lot of lag which reduces a LOT of fps. I think this should be nerfed down despite the fact when its combined with a mineshaft its barely playable. Also they also get stuck on the roof somehow, for this I do not know the reason why this happens.