Sheep mechanics

I know sheep are not terribly exciting topic for a discussion, but I was curious what determines whether sheep becomes yours.

What is the range for scouts to collect sheep? I have watched scouts run by neutral sheep, but sometimes the sheep do not follow.

Also, scouts seem like they are the only unit that can collect sheep. Villagers can not capture neutral sheep (only kill them), but villagers in the vicinity of captured sheep keeps the sheep from being poached by other scouts.

Mills and yurts can automatically attract sheep

Scout, Khan, mill, and ger make the sheep follow/yours.