Hmmm...I replied to this earlier, but my reply is gone.
At any rate, my thoughts are that it can't hurt to send the letters. My phrase for my top three was something to the effect of "I'm ranking you very highly and I look forward to working with you in June." I really liked my top three programs and I would have been happy at any of them, so it wasn't a lie. I did tell my number one program they were number one, but I wouldn't do that unless you absolutely know which program is your number one.