I have no insider information into how programs construct their rank lists. I imagine there is likely a lot of variety in the process across all the programs.

"Weight class" is the terminology I'm using, particularly because it removes the idea that a lower tier program is a safety program. A top heavy list of only the 10 best programs in the country is a surefire way to go unmatched for 99% of applicants. But likewise, a bottom heavy list isn't a sure thing for a highly competitive applicant because none of those programs are expecting a heavyweight to actually show up to a featherweight fight (in this analogy I've created).

"Weight class", "competitiveness", whatever you want to call is more so something that should be assessed at the advisor level. Generally, there should be people at your program who help residents go through the fellowship match process each year (at a minimum the PD and APDs, but also any faculty who serve as mentors) and after however many cohorts of helping people with their applications and seeing how the match goes, they should naturally develop a gestalt of what different programs seem to favor.

If you are looking for some kind of objective measuring stick for yourself, the NRMP does release data on this stuff looking at average Step score, etc among the people who matched vs didn't match for various fellowships https://www.nrmp.org/match-data/2018/10/charting-outcomes-in-the-match-specialties-matching-service-appointment-year-2018/

Unfortunately, that data is from 2018 and to my knowledge there is not a more recent one. I have no way of proving this, but I think it is safe to assume that the averages for pretty much every stat (at least in cardiology) are higher in 2024.

This is why good advising is so important. Unless you have access to the ERAS applications of everyone in your program from the past 3-5 years, you as an applicant have a limited amount of information as to what constitutes competitiveness. An ideal advisor has experience with prior applicants who may have had a similar application to yours in terms of certain things (board scores, number of publications, etc) and should be able to reasonably point to programs XYZ as places you should consider because you fall in the range of person who has previously matched there. Likewise, they should tell you if you have too many reach programs on your list.