Donor Ranking in RE and In General

I have a question regarding Top Donor Reports. I've been working in non-profits for nearly 16 years. I also have a background in research and science (Biology, Ecology, and Chemistry). A few days ago, my supervisor said I was ranking donors in our top donor report incorrectly.

Example: She stated that if someone has donated the same amount, they get assigned the same rank (I agree here), but that the next donor gets assigned NOT the next logical ranking number, but the number they would have gotten if the previous rank had not been adjusted. More specifically, if donors 3 and 4 donated the same amount, they both get assigned a rank of 3, but the next person (#5 originally), would not be assigned Rank #4, they would still be Rank #5. So, what would happen to Rank #4? Person #4 was assigned Rank #3 based on the amount donated, so they can't also be #4 - that would be a Count function. Why is rank #4 being skipped? Logically, that 5th person should get rank #4,as a result of the previous ranking of #3, if ranking is truly based on the amount. It seems like a Count function is getting confused with rank by amount. Can someone clarify this? I'm truly baffled, as a logical person.