Cover letter hell...

They (the mysterious mavens of career counseling) routinely argue that job hunters need to tailor each and every cover letter they send to the particular requirements of the recipient. Since I've been job hunting, I've attempted to do just that. Using my basic "template" I state how I heard about the job, briefly explain my qualifications, outline a couple of relevant experiences, and then close. Here's the problem: I'm applying for many very similar jobs. They want 0-3 years of legal experience in environmental and administrative law, or some variation on that theme. Which makes me wonder how tailored these letters actually have to be. Really, there's only so many different ways I can describe writing a brief on the deliberative process privilege. At some point it begins to seem like a waste of time and resources. I wonder whether the employers reading my applications can actually tell that I've spent good time writing them that letter?