One of the things the rules need to do is ensure that when Wonder Woman complains, "Is there anything Batman can't do with those stupid Batarangs?" there is an answer. Saying "No, Batman can do anything with his Batarangs, but he only throws them three times a day because, well, he just does" is no kind of answer. The Batman player will quite reasonably say, "Well, what if I do throw a fourth Batarang today? What happens then?"
You can't, because you only HAVE 3. Simple and realistic. Batman goes in prepared and saves the magical Batarangs for when they are needed, time for you to think of a different way to win than the magical Batarang. The power of the narrative is more powerful than any ability, thats why Batman can defeat Superman.