I was curious about the number of appointments a congressman can receive if there are other students appointed by the same congressmen currently enrolled at USNA. What is the maximum number of students a congressman can have at USNA at one time?
If there is a qualified applicant, then there will be an appointment in that district charged to the MOC who nominated that individual. It seems that you are looking for something more than you are really asking. There are many reasons why a congressional district can have more than one appointment. It is related to the nomination sources and the other methods to fill the class. The MOC can only have 5 charged to him, typically one a year and every 4th year two, but their are others that may have service connected nominations, come from the NWL or be an athlete or some other under-representative minority that gets a spot as an Additional Appointees.
You should focus on doing the best you can with the opportunities you have and not worry about the things outside your control.