Yes your average Inhuman is stronger then your average Mutant even before Terrigenesis. Without going through an Inhuman's natural physical attributes are better then your average human as they were meant to be a slave-soldier group for the Kree. They also have longer lifespans with the average age being 150 years. Though I think these advancements only belong to Inhumans who has enough of a blood connection to a full Inhuman, meaning the Nuhumans lost this over time with human dna. Based on powers yes some are better though with limited use not as many feats.
No real ranking system like that the closest would be the (old?) Caste system from Attilan and the groups put into it. Say the Warrior Caste with the Royal Guard, and the Security force. Not a lot of info is given to much into these but since the Royal Guard was used in offensive attacks plus protecting the Royals so I can bet after deciding where someone's power would be used best they are tested and put into where they are powers wise. All of this is a guess but I feel it would make sense.