Every detached structure shares one limit
Barns, shops, arenas, detached garages and pumphouses all draw on a single other-structures limit, usually a fixed percentage of the dwelling cover. It is set by formula rather than by what is standing, and on an acre property it is routinely a fraction of what rebuilding would cost.
Animals are not covered property
Horses and livestock are excluded or capped at a token figure on a homeowners form, and the liability that follows an animal is a separate question again. A residential policy on a property with stalls is usually doing less than the owner believes.
Acreage multiplies the liability surface
More land, more structures and more visitors mean more ways for someone to be hurt. The dwelling limit gets reviewed at renewal; the liability limit almost never does, and it is the one a serious claim tests.