Chris- I would stay with what you have got. MOST coyotes will not take on a large dog. Small dogs, however, are like "bait" to a coyote. Our dogs do not weigh much more than yours. Buddy, our male, should weigh a lot more than he does, but as I mentioned, he was a rescue and was never fed when he was young, so he is not as large as he would otherwise be. Yours look like they have quite a bit of shepherd in them, and frankly I've never heard of a coyote around here taking on a shepherd.
Some of the coyote hunters around here use dogs to chase coyotes (not what I consider the best way to hunt them, but that's a whole 'nuther story.)
Some of the dogs they use to chase the coyotes are not much more than 35-45 lbs. The coyotes always run.
It would be very difficult to restrain a LGD to 6 acres. I suppose it could be done, but if you have neighbors who have already shot at your dogs, I would definitely not get one.
My sister had a great pyrneese for a LGD. She loved that dog, and he did his job well. Her husband died of cancer, and after a while she remarried and moved to a new area. Her dog was shot by one of her new neighbors when it went onto his land. It was after coyotes, and I don't know the guy's rationale for shooting him, but as you can imagine my sister was heartbroken.
My sister subsequently replaced her dog with two more GP's. These two tend to stay in the pasture with her goats and chickens. I've seen them clear the fence in a heartbeat when they go after something, though. One day she had two stray rotties get into the pasture with her goats. They were going to have a goat killing fiasco. Her two great pyrenees killed those two big rotweilers.
I don't think I would worry too much about the abilities of your dogs to get the job done.
Best wishes.
Some of the coyote hunters around here use dogs to chase coyotes (not what I consider the best way to hunt them, but that's a whole 'nuther story.)

It would be very difficult to restrain a LGD to 6 acres. I suppose it could be done, but if you have neighbors who have already shot at your dogs, I would definitely not get one.
My sister had a great pyrneese for a LGD. She loved that dog, and he did his job well. Her husband died of cancer, and after a while she remarried and moved to a new area. Her dog was shot by one of her new neighbors when it went onto his land. It was after coyotes, and I don't know the guy's rationale for shooting him, but as you can imagine my sister was heartbroken.

My sister subsequently replaced her dog with two more GP's. These two tend to stay in the pasture with her goats and chickens. I've seen them clear the fence in a heartbeat when they go after something, though. One day she had two stray rotties get into the pasture with her goats. They were going to have a goat killing fiasco. Her two great pyrenees killed those two big rotweilers.

I don't think I would worry too much about the abilities of your dogs to get the job done.
Best wishes.