verb (used with object), hired, hiring. 1. to engage the services of (a person or persons) for wages or other payment: to hire a clerk. 2. to engage the temporary use of at a set price; rent: to hire a limousine. noun.
Batman is not a superhero but in the world of DC and Marvel comics there are Superheroes and Heroes. So Batman is a hero so is Green Arrow. first of all you're wrong you don't need powers to classified as a super hero. Batman is a hero because he puts on a costume and does good deeds and and makes the world a safer place, and there are actually a lot of super characters without powers.
I think Batman is stronger. If you know your weakness and not rely on strength, you are stronger. Batman knows what are the weakness of all justice league member. In Justice League: Doom, he has plan for everyone even for him. In any case if something happen to League member world does not suffer.