I think ranking systems can be a little damaging for stories.
I'm assuming this is for battles, correct me otherwise
If by ranking you mean like A > B > C > D battles could be less interesting as they would depend on who has more of what, and usually resumes in the characters either having good durability or good energy stats to rise victorious, or the rankings being taken aside when a villain is too powerful in stats, that the only way for the MC's to defeat him/her is to use deus ex machina.
I prefer something reactive, like a cycle:
Fire beats air, air beats earth, earth beats water, water beats fire
Rock beats scissors, scissors beats paper, papers beats rock
and so on.
This give everyone room to shine, yet some difficulties when facing someone who is theoretically stronger than them, but that can still be defeatable.