That everyone on the Enterprise in TOS was an officer. Silly. Just damned silly and impractical.
I can buy GR's thinking on this. TOS was made in the era of the NASA astronaut-hero, the days of John Glenn and others. At that time, all NASA astronauts were college grads and all were officers.
GR wanted his TOS crew to be qualified astronauts, same as NASA, only in a future century. NASA only had officers as their astronauts, GR wanted no less. So okay, everyone on the Enterprise is an astronaut and an officer.
I totally get this, and understand how GR got to where he got. and that is totally huny-dory in a Gemini or Apollo capsule with two or three guys.
However, this ain't gonna work in a large fleet of vessels, or in even one vessel with a crew of hundreds. you have to have a solid chain of command in place and you need it to have a very definite structure. Despite the fact that Picard seemed to run his ship by committee, I think it is a very bad idea.