Ultimately, all that matters is that you submit letters from people who know you well and can vouch for your excellence. So that's all right, or you could switch out the letter. It's up to you.Right now, my committee letter packet includes:
1) the committee letter written by my prehealth advisor
2) a science professor
3) my research mentor
4) two physicians I have worked with
5) a physician assistant
6) a humanities professor
Would it strengthen my packet if I switch out the physician assistant letter for another science professor letter?