Is there a way to add a template to multiple tasks in one project?

I have a project where the parent tasks are for example, Set 1, Set 2, etc. Under each of these we need the same set of sub tasks. Since we don't know the number of sets up front (could be 2, could be 50), I'm wondering if there is a way to append the same template to multiple parent tasks at the same time? Or do we need to copy them over and over?