Started putting up woven wire fencing around the pasture. About a $2k investment, but the goats kept breaking the electric. Had to be done. About 250' complete, About 1000' to go.
4'. The goats could jump it if they were sufficiently motivated. I have a fence stretching jig, plus the tractor. 25hp is plenty, once it's maneuvered into place.
A couple years ago, my neighbor thought she might get a goat. I think/hope she's forgotten about that idea. I would have to have a very serious talk with her if she gets one.
They don't/can't keep their chickens in the run. A goat on the loose would be a HUGE issue. Michigan is a "fence in" state.