@gonnif has explained this before and I have inserted his thorough explanation below. Long story short, you will be fine. School committee or letter packets trump any individual school letter requirements.
"When you are getting letters, they fall into two categories
Committee Letter (with evaluation) or Letter Packet (only cover letter)
, where you follow the requirements of the UG institution and it is acceptable by virtually all medical schools
OR
Individual Letters , where you follow the requirements of each individual medical school
**The number of letters in a committee letter or letter packet is immaterial, It is not under the requirements of indivdual letters.
**The vast majority of medical schools require, recommend, or prefer committee letters. I would say that letter packets are treated a bit more like committee letters rather than indivdual letters.
**My recommendation is no more than 4 to 6 letters as more can be interpreted in various negative ways by an adcom
---Are just sending more of the same because you are arrogant, showing off, egoistical? Doesnt the rest of your app say that?
---Are you sending more because you have a weakness in your app you are trying to overcome or hide?
Hence, like everything else in an applicant, adcoms want to see balance.
Section 6 of the AMCAS® application: Letters of Evaluation
Letter Types
AMCAS accepts three different types of letters. Each letter type is equivalent to one letter entry.
Committee Letter: A letter authored by a pre-health committee or pre-health advisor and intended to represent your institution’s evaluation of you. A Committee Letter may or may not include additional letters written in support of your application. This is sometimes called a Composite Letter.
Letter Packet: A packet or set of letters assembled and distributed by your institution, often by the institution’s career center. A Letter Packet may include a cover sheet from your pre-health committee or advisor. However, unlike to a Committee Letter, a Letter Packet does not include an evaluative letter from your pre-health committee or advisor.
Individual Letter: A letter written by, and representing, a single letter author. If you have already included an Individual Letter within either a Committee Letter or a Letter Packet, do not add a separate entry for that letter. "
