We had a couple of similar situations. Really just due to the fact that no one knew how the new Leaveweb worked until the boss got a couple of PTDY requests.
I just have my guys tell me about any requests they are going to put in about a month in advance, and then send that to my super, who in turn emails an OK to the commander. That way no one feels like that have been blindsided. And it sounds like a lot, but really it's just, "Hey, SrA so-and-so is headed to a softball tournament--I have no issues with it."