My school sent a packet as well. So I too did not have committee letters. Now lets suppose you have 5 letters in your file. The way it worked at my school was that all 5 letters went out, regardless of if a school only wanted 3. So I couldn't choose 3 out of the 5 to send out. All 5 went out. So when a school asked me for only 3 recommendation letters, I listed the names of my 3 recommenders whom I thought wrote me the best letters. The in turn, the medical school would only read those 3 letters, instead of all 5.
Hope this helps
🙂