With the fence piece, just wait for them to place it down. Sometimes when you choose where to put it, like in that gap, its only the ghost image of it that looks out of place. But when they actually put it in, it will go where you wanted it to. Some people cancel it before it gets there, thinking that it will be wrong.
A Geomancer job can give more access to the Golems, and could be a choice of bringing them on a re-embark. Or, there are also some mods that allow easier access to getting different types of Golems.
I recommend Auto Golems Guns 
You could try to make part of your pasture in a cave, with some of it existing on the grass in front of the mountain cave entrance. It works in vanilla Stonehearth, but I’m not sure if ACE would restrict that.
1 Like