In my ranking system the C ranks can fight 1,000s of normal humans so they are not that weak, even if S rank can fight 1,000s of them. A rank can only fight 100s of them. F rank is a normal human although there can be lower ranks for cripples and weaker species. And babies. They don't bother to get ranks though unless part of some funny gag. S ranks aren't even found on a lot of worlds so there might be one per every 10 or so planets at most. If they are on a planet they could probably conquer it if they felt like it, given that all the inhabitants are only F rank. The main heroes of one of my stories are S rank but there's higher ranks such as the one right above them called Legendary that one of their main opponent is.
That's some academy allowing studies to get ribs broken.
in the battle for rankings they allow anything but killing your opponent...
and the academy works in teams and each team must have at least five people
1. A captain which happens to be our hero, the academy chooses captains from anyone with leader potential though some of them get to decline this offer in order to just be a second
2. They have to have at least one mage in their group and so the academy also has different classes for different roles and by classes I mean classes not as in job classes...
3. The team must have at least two other members with at least one of them being a guide since it no use being a team if you have no one with a sense of direction which was taught in the first day so everyone would understand why they needed a guide
4. This team of four must have at least one veteran who is either retired, a former graduate who became strong but no longer has a team, or they elite teams who are so strong when graduating that they do not need a veteran which is a special exception
Currently as things are the hero is currently C-Rank, the girl who beat him is also C-Rank, the girl who happens to be his mage is D-Rank and still learning, the guide is a half-beast(mistaken for a demon) who got given special permission to attend the academy but is the hero's responsibility which lead him to have to pay the last of his ten silver coins due to the kid being hungry and eating ten lunches during the break period. One silver coin gets one good lunch, copper and bronze coins are used on the streets, gold coins are for the really expensive food and stuff or weapons etc...
Currently the hero is at five coppers... and they currently don't have a veteran yet his still going to join them, right now his just watching them from the background like some weird stalker