Yes, the Gorosei possess greater authority and for that reason they command the admirals, it's like a position, there's the chief and their subordinates, and Saturn treated Kizaru the whole time as a subordinate and not as equals, this is literally clear from the beginning of the arc, with Kizaru even going as far as to serve tea for Saturn (taking on the role of a waiter).
The real question doesn't lie in "Whether they are subordinates" because the manga has already answered that, the question lies in "Whether they are Yc3 or not?!" which I agree with, when we compare Gorosei, Yonkou, and Admirals, the Admirals become Yc3 in comparison to the other two major figures.
Yonko Luffy, for example, is so strong that he defeated Kizaru with one blow.