The butter is a range because it depends on how much you want. Since it's not mixed into the rest of the ingredients, you can go a bit light and still have the same effect of frying the cobbler.

The fruit is a range because it isn't mixed into the batter either. So put as much fruit as you want. You don't want too little fruit, or you won't have enough spread throughout to really make it a cobbler. You don't want too much or the whole thing will fall apart. Use whatever is convenient and don't worry about being exactly on the dot with 1 or 2 pints.