Working 2 dogs at once

   Sometimes it's just easier to give in and not fight with them.  I wanted to use Dually to sort some sheep but Dare would not stay  outside the fence so I used both of them. I flanked them both and then when I wanted to put them out a gate, one wanted to hold (Dare) and one wanted to push so Dare got a rock  can thrown at him and it connected with his head.  He gave in and went where I asked him to.  I didn't think  much more about it, but later this afternoon when I took him out to sort the sheep back to their original pens, he actually stopped and sat every time I asked him to Stop.  That was unprecedented and the only thing I can attribute it to is the can in the head.   Silly dog.  But what a hard head.