I'm against electric fencing for so many reasons.
I think that any dog could go over the line for something they really want if they are determined.
Other animals can get IN the electric fence because they do not have the collars on, and if your dogs are too afraid to cross the line they will be easy prey for other animals.
Stealing. Your dogs would be targets for theives who could simply remove the collar and run off with the dog. There's no fence to deter them and your dogs are in full view.
Those are a few of my reasons
. I think Xpens or Super Yards linked together for supervised play would be a better solution