Green enemy uses sheeps to capture my mines near there borders :/ im no expert at the game, but im pretty sure this isnt suppose to happen

I guess the shepherds saw a chance to fill their pockets with gold. Great initiative, I'd take over the sheep and send them to an important posting. The main course at a banquet sounds important enough for me :)

Sounds like it's a non-intentional functionality, but not sure I'd call it a bug. I mean, if you can't stop a slow unit of defenseless sheep your empire's in a sorry state. And as I said, there _are_ probably some herdsmen with that flock ;)