Sheep need less copper than goats. Some mineral supplements that are great for goats can be toxic to sheep. Sheep are more likely to overeat than goats. Be careful about turning sheep into a lush pasture or freefeeding them more hay than they usually eat. In our area, enterotoxemia has not been a problem for goats on a controlled diet.
Sheep are grazers, goats are browsers.
That means sheep are probably better weed eaters, since they eat grasses and other plants all the way down to the ground. Goats, on the other hand, nibble here and there, sampling a variety of bushes and leaves. Sheep, except those that are tamed by bottlefeeding, are more skittish than goats. Their instinct is to flee, not fight. Sheep milk is higher in fat than goat milk.